TOP234YN [POWERINT]

IC OFFLINE SWIT OVP UVLO TO220;
TOP234YN
型号: TOP234YN
厂家: Power Integrations    Power Integrations
描述:

IC OFFLINE SWIT OVP UVLO TO220

文件: 总36页 (文件大小:1767K)
中文:  中文翻译
下载:  下载PDF数据表文档文件
This product is not recommended for new designs.  
TOP232-234  
TOPSwitch-FXFamily  
Design Flexible, EcoSmart, Integrated  
Off-Line Switcher  
Product Highlights  
+
AC  
IN  
DC  
Lower System Cost, High Design Flexibility  
OUT  
-
Features eliminate or reduce cost of external components  
Fully integrated soft-start for minimum stress/overshoot  
Externally settable accurate current limit  
Wider duty cycle for more power, smaller input capacitor  
Line under-voltage (UV) detection: no turn off glitches  
Line overvoltage (OV) shutdown extends line surge limit  
D
S
M
CONTROL  
C
Line feed-forward with maximum duty cycle (DCMAX  
reduction rejects ripple and limits DCMAX at high line  
)
TOPSwitch-FX  
F
Single resistor sets OV/UV thresholds, DCMAX reduction  
Frequency jittering reduces EMI and EMI filtering costs  
Regulates to zero load without dummy loading  
132 kHz frequency reduces transformer/power supply size  
Half frequency option for video applications  
PI-2503-062515  
Figure 1. Typical Flyback Application.  
Hysteretic thermal shutdown for automatic recovery  
Large thermal hysteresis prevents PC board overheating  
Standard packages with omitted pins for large creepage  
Active-on and active-off remote ON/OFF capability  
Synchronizable to a lower frequency  
OUTPUT POWER TABLE  
Product3  
230 VAC 1ꢀ5  
Open  
8ꢀ-26ꢀ VAC  
Open  
Adapter1  
Adapter1  
Frame2  
Frame2  
EcoSmartEnergy Efficient  
Cycle skipping reduces no-load consumption  
Reduced consumption in remote off mode  
Half frequency option for high efficiency standby  
Allows shutdown/wake-up via LAN/input port  
TOP232P  
TOP232G  
TOP232Y  
9 W  
15 W  
25 W  
25 W  
50 W  
30 W  
75 W  
6.5 W  
7 W  
10 W  
15 W  
15 W  
30 W  
20 W  
45 W  
10 W  
13 W  
20 W  
16 W  
30 W  
TOP233P  
TOP233G  
TOP233Y  
TOP234P  
TOP234G  
TOP234Y  
Description  
9 W  
TOPSwitch™-FX uses the proven TOPSwitch topology and  
cost effectively integrates many new functions that reduce  
system cost and, at the same time, improve design flexibility,  
performance and energy efficiency. Like TOPSwitch, the  
high-voltage power MOSFET, PWM control, fault protection  
and other control circuitry are all integrated onto a single  
CMOS chip, but with two added terminals. The first one is a  
MULTI-FUNCTION (M) pin, which implements programmable  
line OV/UV shutdown and line feed-forward/DCMAX reduction  
with line voltage. The same pin can be used instead to  
externally set an accurate current limit. In either case, this pin  
can also be used for remote ON/OFF or to synchronize the  
oscillator to an external, lower frequency signal. The second  
added terminal is the FREQUENCY (F) pin and is available only  
in the Y package. This pin provides the half frequency option  
when connected to CONTROL (C) instead of SOURCE (S).  
The features on the new pins can be disabled by shorting  
them to the SOURCE, which allows the device to operate in a  
three terminal TOPSwitch mode, but with the following new  
transparent features: soft-start, cycle skipping, 132 kHz  
15 W  
11 W  
20 W  
Table 1.  
Notes:  
1. Typical continuous power in a non-ventilated enclosed adapter measured at  
50 ˚C ambient.  
2. Maximum practical continuous power in an open frame design with adequate  
heat sinking, measured at 50 ˚C ambient. See key applications section for  
detailed conditions.  
3. Packages: P: DIP-8B, G: SMD-8B, Y: TO-220-7B.  
hysteretic thermal shutdown and larger creepage. In addition,  
all critical parameters such as frequency, current limit, PWM  
gain, etc. have tighter temperature and absolute tolerances  
compared to the TOPSwitch-II family. Higher current limit  
accuracy and larger DCMAX, when combined with other  
features allow for a 10% to 15% higher power capability on the  
TOPSwitch-FX devices compared to equivalent TOPSwitch-II  
devices for the same input/output conditions.  
switching frequency, frequency jittering, wider DCMAX  
,
www.power.com  
June 2015  
This Product is Covered by Patents and/or Pending Patent Applications.  
TOP232-234  
Section List  
Pin Functional Description ....................................................................................................................................... 3  
TOPSwitch-FX Family Functional Description ........................................................................................................ 4  
CONTROL (C) Pin Operation.................................................................................................................................... 4  
Oscillator and Switching Frequency.......................................................................................................................... 5  
Pulse Width Modulator and Maximum Duty Cycle.................................................................................................... 5  
Minimum Duty Cycle and Cycle Skipping ................................................................................................................. 6  
Error Amplifier .......................................................................................................................................................... 6  
On-chip Current Limit with External Programability................................................................................................... 6  
Line Undervoltage Detection (UV)............................................................................................................................. 6  
Line Overvoltage Shutdown (OV).............................................................................................................................. 7  
Line Feed-Forward with DCMAX Reduction ................................................................................................................ 7  
Remote ON/OFF and Synchronization...................................................................................................................... 7  
Soft-Start................................................................................................................................................................. 8  
Shutdown/Auto-Restart ........................................................................................................................................... 8  
Hysteretic Over-Temperature Protection................................................................................................................... 8  
Bandgap Reference ................................................................................................................................................. 8  
High-Voltage Bias Current Source............................................................................................................................ 8  
Using FREQUENCY and MULTI-FUNCTION Pins .................................................................................................... 9  
FREQUENCY (F) Pin Operation ................................................................................................................................ 9  
MULTI-FUNCTION (M) Pin Operation........................................................................................................................ 9  
Typical Uses of FREQUENCY (F) Pin ...................................................................................................................... 11  
Typical Uses of MULTI-FUNCTION (M) Pin ............................................................................................................. 12  
Application Examples ............................................................................................................................................. 14  
A High Efficiency, 30 W, Universal Input Power Supply ........................................................................................... 14  
35 W Multiple Output Power Supply....................................................................................................................... 15  
17 W PC Standby Power Supply ........................................................................................................................... 16  
Processor Controlled Supply Turn On/Off............................................................................................................... 17  
Key Application Considerations .............................................................................................................................. 19  
TOPSwitch-FX vs. TOPSwitch-ll............................................................................................................................. 19  
TOPSwitch-FX Design Considerations ................................................................................................................... 20  
TOPSwitch-FX Selection.................................................................................................................................. 20  
Input Capacitor................................................................................................................................................ 20  
Primary Clamp and Output Reflected Voltage VOR .......................................................................................... 20  
Output Diode................................................................................................................................................... 21  
Soft-Start......................................................................................................................................................... 21  
EMI ................................................................................................................................................................. 21  
Transformer Design.......................................................................................................................................... 21  
Standby Consumption..................................................................................................................................... 23  
TOPSwitch-FX Layout Considerations.................................................................................................................... 23  
Primary Side Connections ............................................................................................................................... 23  
Y-Capacitor ..................................................................................................................................................... 23  
Heat Sinking.................................................................................................................................................... 23  
Quick Design Checklist .......................................................................................................................................... 23  
Design Tools .......................................................................................................................................................... 23  
Product Specifications and Test Conditions .......................................................................................................... 24  
Typical Performance Characteristics ..................................................................................................................... 30  
Package Outlines .................................................................................................................................................... 34  
2
Rev. C 06/15  
www.power.com  
TOP232-234  
CONTROL (C)  
DRAIN (D)  
0
1
V
C
Z
INTERNAL  
SUPPLY  
C
SHUNT REGULATOR/  
ERROR AMPLIFIER  
+
-
SOFT START  
5.8 V  
4.8 V  
-
5.8 V  
+
INTERNAL UV  
COMPARATOR  
I
FB  
V
I (LIMIT)  
CURRENT  
LIMIT  
ADJUST  
-
8  
ON/OFF  
+
SHUTDOWN/  
AUTO-RESTART  
V
+ V  
BG  
T
CURRENT LIMIT  
COMPARATOR  
MULTI-  
FUNCTION (M)  
HYSTERETIC  
THERMAL  
SHUTDOWN  
V
BG  
CONTROLLED  
TURN-ON  
GATE DRIVER  
STOP  
SOFT-  
OV/UV  
START  
D
LINE  
SENSE  
MAX  
DC  
DC  
MAX  
MAX  
CLOCK  
SAW  
FREQUENCY (F)  
(Y Package Only)  
S
R
Q
Q
HALF  
FREQUENCY  
-
LEADING  
EDGE  
BLANKING  
+
OSCILLATOR WITH JITTER  
PWM  
COMPARATOR  
R
E
SOURCE (S)  
PI-2535-062615  
Figure 2. Functional Block Diagram.  
Pin Functional Description  
DRAIN (D) Pin:  
High-voltage power MOSFET drain output. The internal  
start-up bias current is drawn from this pin through a switched  
high-voltage current source. Internal current limit sense point  
for drain current.  
SOURCE (S) Pin:  
Output MOSFET source connection for high-voltage power  
return. Primary side control circuit common and reference  
point.  
Tab Internally  
Connected to SOURCE Pin  
CONTROL (C) Pin:  
Error amplifier and feedback current input pin for duty cycle  
control. Internal shunt regulator connection to provide internal  
bias current during normal operation. It is also used as the  
connection point for the supply bypass and auto-restart/  
compensation capacitor.  
7
D
5
4
3
F
S
M
1
C
MULTI-FUNCTION (M) Pin:  
Y Package (TO-220-7B)  
Input pin for OV, UV, line feed-forward with DCMAX reduction,  
external set current limit, remote ON/OFF and synchronization.  
A connection to SOURCE pin disables all functions on this pin  
and makes TOPSwitch-FX operate in simple three terminal  
mode (like TOPSwitch-II).  
1
2
M
S
8
7
S
S
3
4
S
C
FREQUENCY (F) Pin: (Y package only)  
5
D
Input pin for selecting switching frequency: 132 kHz if  
connected to SOURCE pin and 66 kHz if connected to  
CONTROL pin. The switching frequency is internally set for  
132 kHz only operation in P and G packages.  
P Package (DIP-8B)  
G Package (SMD-8B)  
PI-2501-031901  
Figure 3. Pin Configuration.  
3
Rev. C 06/15  
www.power.com  
TOP232-234  
TOPSwitch-FX Family Functional Description  
Auto-restart  
ICD1  
Like TOPSwitch, TOPSwitch-FX is an integrated switched  
mode power supply chip that converts a current at the control  
input to a duty cycle at the open drain output of a high-voltage  
power MOSFET. During normal operation the duty cycle of the  
power MOSFET decreases linearly with increasing CONTROL  
pin current as shown in Figure 4.  
IB  
78  
Slope = PWM Gain  
47  
I
= 140 µA  
M
In addition to the three terminal TOPSwitch features, such as  
the high-voltage start-up, the cycle-by-cycle current limiting,  
loop compensation circuitry, auto-restart, thermal shutdown,  
etc., the TOPSwitch-FX incorporates many additional functions  
that reduce system cost, increase power supply performance  
and design flexibility. A patented high-voltage CMOS  
technology allows both the high-voltage power MOSFET and  
all the low voltage control circuitry to be cost effectively  
integrated onto a single monolithic chip.  
I
< I  
M(DC)  
M
I
= 190 µA  
M
1.5  
1.5 1.9  
5.5 5.9  
IC (mA)  
PI-2504-072799  
Figure 4. Relationship of Duty Cycle to CONTROL Pin Current.  
Two terminals, FREQUENCY (available only in Y package) and  
MULTI-FUNCTION, have been added to implement some of  
the new functions. These terminals can be connected to the  
SOURCE pin to operate the TOPSwitch-FX in a TOPSwitch-  
like three terminal mode. However, even in this three terminal  
mode, the TOPSwitch-FX offers many new transparent  
features that do not require any external components:  
The FREQUENCY pin in the TO-220 package sets the  
switching frequency to the default value of 132 kHz when  
connected to SOURCE pin. A half frequency option can be  
chosen by connecting this pin to CONTROL pin instead.  
Leaving this pin open is not recommended.  
CONTROL (C) Pin Operation  
The CONTROL pin is a low impedance node that is capable of  
receiving a combined supply and feedback current. During  
normal operation, a shunt regulator is used to separate the  
feedback signal from the supply current. CONTROL pin  
voltage VC is the supply voltage for the control circuitry  
including the MOSFET gate driver. An external bypass  
capacitor closely connected between the CONTROL and  
SOURCE pins is required to supply the instantaneous gate  
drive current. The total amount of capacitance connected to  
this pin also sets the auto-restart timing as well as control loop  
compensation.  
1. A fully integrated 10 ms soft-start reduces peak currents  
and voltages during start-up and practically eliminates  
output overshoot in most applications.  
2. DCMAX of 78% allows smaller input storage capacitor, lower  
input voltage requirement and/or higher power capability.  
3. Cycle skipping at minimum pulse width achieves regulation  
and very low power consumption at no load.  
4. Higher switching frequency of 132 kHz reduces the  
transformer size with no noticeable impact on EMI or on  
high line efficiency.  
5. Frequency jittering reduces EMI.  
6. Hysteretic over-temperature shutdown ensures automatic  
recovery from thermal fault. Large hysteresis prevents circuit  
board overheating.  
7. Packages with omitted pins and lead forming provide large  
DRAIN creepage distance.  
When rectified DC high-voltage is applied to the DRAIN pin  
during start-up, the MOSFET is initially off, and the CONTROL  
pin capacitor is charged through a switched high-voltage  
current source connected internally between the DRAIN and  
CONTROL pins. When the CONTROL pin voltage VC reaches  
approximately 5.8 V, the control circuitry is activated and the  
soft-start begins. The soft-start circuit gradually increases the  
duty cycle of the MOSFET from zero to the maximum value  
over approximately 10 ms. If no external feedback/supply  
current is fed into the CONTROL pin by the end of the  
soft-start, the high-voltage current source is turned off and the  
CONTROL pin will start discharging in response to the supply  
current drawn by the control circuitry. If the power supply is  
designed properly, and no fault condition such as open loop or  
shorted output exists, the feedback loop will close, providing  
external CONTROL pin current, before the CONTROL pin  
voltage has had a chance to discharge to the lower threshold  
voltage of approximately 4.8 V (internal supply under-voltage  
lockout threshold). When the externally fed current charges the  
CONTROL pin to the shunt regulator voltage of 5.8 V, current  
8. Tighter absolute tolerances and smaller temperature vari-  
ations on switching frequency, current limit and PWM gain.  
The MULTI-FUNCTION pin is usually used for line sensing by  
connecting a resistor from this pin to the rectified DC high-  
voltage bus to implement line over-voltage (OV)/under-voltage  
(UV) and line feed-forward with DCMAX reduction. In this mode,  
the value of the resistor determines the OV/UV thresholds and  
the DCMAX is reduced linearly starting from a line voltage above  
the under-voltage threshold. In high efficiency applications, this  
pin can be used in the external current limit mode instead, to  
reduce the current limit externally (to a value close to the  
operating peak current), by connecting the pin to SOURCE  
through a resistor. The same pin can also be used as a  
remote ON/OFF and a synchronization input in both modes.  
4
Rev. C 06/15  
www.power.com  
TOP232-234  
in excess of the consumption of the chip is shunted to  
SOURCE through resistor RE as shown in Figure 2. This  
current flowing through RE controls the duty cycle of the power  
MOSFET to provide closed loop regulation. The shunt  
regulator has a finite low output impedance ZC that sets the  
gain of the error amplifier when used in a primary feedback  
configuration. The dynamic impedance ZC of the CONTROL  
pin together with the external CONTROL pin capacitance sets  
the dominant pole for the control loop.  
sawtooth waveform for the pulse width modulator. The  
oscillator sets the pulse width modulator/current limit latch at  
the beginning of each cycle.  
The nominal switching frequency of 132 kHz was chosen to  
minimize transformer size while keeping the fundamental EMI  
frequency below 150 kHz. The FREQUENCY pin (available  
only in TO-220 package), when shorted to the CONTROL pin,  
lowers the switching frequency to 66 kHz (half frequency)  
which may be preferable in some cases such as noise  
sensitive video applications or a high efficiency standby mode.  
Otherwise, the FREQUENCY pin should be connected to the  
SOURCE pin for the default 132 kHz. Trimming of the current  
reference improves oscillator frequency accuracy.  
When a fault condition such as an open loop or shorted output  
prevents the flow of an external current into the CONTROL pin,  
the capacitor on the CONTROL pin discharges towards 4.8 V.  
At 4.8 V auto-restart is activated which turns the output MOSFET  
off and puts the control circuitry in a low current standby  
mode. The high-voltage current source turns on and charges  
the external capacitance again. A hysteretic internal supply  
under-voltage comparator keeps VC within a window of  
typically 4.8 to 5.8 V by turning the high-voltage current source  
on and off as shown in Figure 5. The auto-restart circuit has a  
divide-by-8 counter which prevents the output MOSFET from  
turning on again until eight discharge/charge cycles have  
elapsed. This is accomplished by enabling the output MOSFET  
only when the divide-by-8 counter reaches full count (S7). The  
counter effectively limits TOPSwitch-FX power dissipation by  
reducing the auto-restart duty cycle to typically 4%. Auto-  
restart mode continues until output voltage regulation is again  
achieved through closure of the feedback loop.  
To further reduce the EMI level, the switching frequency is  
jittered (frequency modulated) by approximately 4 kHz at  
250 Hz (typical) rate as shown in Figure 6. Figure 28 shows  
the typical improvement of EMI measurements with frequency  
jitter.  
Pulse Width Modulator and Maximum Duty Cycle  
The pulse width modulator implements voltage mode control  
by driving the output MOSFET with a duty cycle inversely  
proportional to the current into the CONTROL pin that is in  
excess of the internal supply current of the chip (see Figure 4).  
The excess current is the feedback error signal that appears  
across RE (see Figure 2). This signal is filtered by an RC  
network with a typical corner frequency of 7 kHz to reduce the  
effect of switching noise in the chip supply current generated  
Oscillator and Switching Frequency  
The internal oscillator linearly charges and discharges an  
internal capacitance between two voltage levels to create a  
VUV  
VLINE  
0 V  
S0  
S0  
S7  
S1  
S2  
S6  
S7 S0  
S1  
S2  
S6  
S7  
S1 S2  
S6  
S7  
S7  
5.8 V  
4.8 V  
VC  
0 V  
VDRAIN  
0 V  
VOUT  
0 V  
1
2
3
2
4
Note: S0 through S7 are the output states of the auto-restart counter  
PI-2545-082299  
Figure 5. Typical Waveforms for (1) Power Up (2) Normal Operation (3) Auto-restart (4) Power Down .  
Rev. C 06/15  
www.power.com  
TOP232-234  
by the MOSFET gate driver. The filtered error signal is  
compared with the internal oscillator sawtooth waveform to  
generate the duty cycle waveform. As the control current  
increases, the duty cycle decreases. A clock signal from the  
oscillator sets a latch which turns on the output MOSFET. The  
pulse width modulator resets the latch, turning off the output  
MOSFET. Note that a minimum current must be driven into  
the CONTROL pin before the duty cycle begins to change.  
136 kHz  
Switching  
Frequency  
128 kHz  
4 ms  
VDRAIN  
The maximum duty cycle, DCMAX, is set at a default maximum  
value of 78% (typical). However, by connecting the MULTI-  
FUNCTION pin to the rectified DC high-voltage bus through a  
resistor with appropriate value, the maximum duty cycle can  
be made to decrease from 78% to 38% (typical) as shown in  
Figure 8 when input line voltage increases (see line feed-  
forward with DCMAX reduction).  
Time  
Figure 6. Switching Frequency Jitter.  
internally. However, with a resistor connected between  
MULTI-FUNCTION pin and SOURCE pin, current limit can be  
programmed externally to a lower level between 40% and  
100% of the default current limit. Please refer to the graphs in  
the typical performance characteristics section for the  
selection of the resistor value. By setting current limit low, a  
TOPSwitch-FX that is bigger than necessary for the power  
required can be used to take advantage of the lower RDS(ON) for  
higher efficiency. With a second resistor connected between  
the MULTI-FUNCTION pin and the rectified DC high-voltage  
bus providing a small amount of feed-forward current, a true  
power limiting operation against line variation can be  
implemented. When using an RCD clamp, this feed-forward  
technique reduces maximum clamp voltage at high line  
allowing for higher reflected voltage designs. The current limit  
comparator threshold voltage is temperature compensated to  
minimize the variation of the current limit due to temperature  
related changes in RDS(ON) of the output MOSFET.  
Minimum Duty Cycle and Cycle Skipping  
To maintain power supply output regulation, the pulse width  
modulator reduces duty cycle as the load at the power supply  
output decreases. This reduction in duty cycle is proportional  
to the current flowing into the CONTROL pin. As the CONTROL  
pin current increases, the duty cycle reduces linearly towards  
a minimum value specified as minimum duty cycle, DCMIN  
.
After reaching DCMIN, if CONTROL pin current is increased  
further by approximately 0.4 mA, the pulse width modulator  
will force the duty cycle from DCMIN to zero in a discrete step  
(refer to Figure 4). This feature allows a power supply to  
operate in a cycle skipping mode when the load at its output  
consumes less power than the power that TOPSwitch-FX  
delivers at minimum duty cycle, DCMIN. No additional control is  
needed for the transition between normal operation and cycle  
skipping. As the load increases or decreases, the power  
supply automatically switches between normal operation and  
cycle skipping mode as necessary.  
The leading edge blanking circuit inhibits the current limit  
comparator for a short time after the output MOSFET is turned  
on. The leading edge blanking time has been set so that, if a  
power supply is designed properly, current spikes caused by  
primary-side capacitances and secondary-side rectifier  
reverse recovery time will not cause premature termination of  
the switching pulse.  
Cycle skipping may be avoided, if so desired, by connecting a  
minimum load at the power supply output such that the duty  
cycle remains at a level higher than DCMIN at all times.  
Error Amplifier  
The shunt regulator can also perform the function of an error  
amplifier in primary feedback applications. The shunt regulator  
voltage is accurately derived from a temperature-compensated  
bandgap reference. The gain of the error amplifier is set by the  
CONTROL pin dynamic impedance. The CONTROL pin  
clamps external circuit signals to the VC voltage level. The  
CONTROL pin current in excess of the supply current is  
separated by the shunt regulator and flows through RE as a  
voltage error signal.  
The current limit can be lower for a short period after the  
leading edge blanking time as shown in Figure 33. This is due  
to dynamic characteristics of the MOSFET. To avoid triggering  
the current limit in normal operation, the drain current  
waveform should stay within the envelope shown.  
Line Undervoltage Detection (UV)  
At power up, UV keeps TOPSwitch-FX off until the input line  
voltage reaches the undervoltage threshold. At power down,  
UV prevents auto-restart attempts after the output goes out of  
regulation. This eliminates power down glitches caused by  
the slow discharge of input storage capacitor present in  
applications such as standby supplies. A single resistor  
connected from the MULTI-FUNCTION pin to the rectified DC  
high-voltage bus sets UV threshold during power up. Once the  
power supply is successfully turned on, UV is disabled to  
On-Chip Current Limit with External Programmability  
The cycle-by-cycle peak drain current limit circuit uses the  
output MOSFET ON-resistance as a sense resistor. A current  
limit comparator compares the output MOSFET on-state drain  
to source voltage, VDS(ON) with a threshold voltage. High drain  
current causes VDS(ON) to exceed the threshold voltage and  
turns the output MOSFET off until the start of the next clock  
cycle. The default current limit of TOPSwitch-FX is preset  
6
Rev. C 06/15  
www.power.com  
TOP232-234  
allow extended input voltage operating range. Input voltage is  
not checked again until the power supply loses regulation and  
attempts another turn-on. This is accomplished by enabling  
the UV comparator only when the divide-by-8 counter used in  
auto-restart reaches full count (S7) which is also the state that  
the counter is reset to at power up (see Figure 5). The UV  
feature can be disabled independent of OV feature as shown  
in Figure 16.  
Remote ON/OFF and Synchronization  
TOPSwitch-FX can be turned on or off by controlling the  
current into or out from the MULTI-FUNCTION pin (see Figure  
8). This allows easy implementation of remote ON/OFF control  
of TOPSwitch-FX in several different ways. A transistor or an  
optocoupler output connected between the MULTI-FUNCTION  
pin and the SOURCE pin implements this function with  
“active-on” (Figure 19) while a transistor or an optocoupler  
output connected between the MULTI-FUNCTION pin and the  
CONTROL pin implements the function with “active-off”  
(Figure 20).  
Line Overvoltage Shutdown (OV)  
The same resistor used for UV also sets an overvoltage  
threshold which, once exceeded, will force TOPSwitch-FX  
output into off-state. The ratio of OV and UV thresholds is  
preset at 4.5 as can be seen in Figure 8. This feature turns off  
the TOPSwitch-FX power MOSFET when the rectified DC  
high-voltage exceeds the OV threshold. When the MOSFET is  
off, the rectified DC high-voltage surge capability is increased  
to the voltage rating of the MOSFET (700 V), due to the  
absence of the reflected voltage and leakage spikes on the  
drain. Small amount of hysteresis is provided on the OV  
threshold to prevent noise triggering. The OV feature can be  
disabled independent of UV feature as shown in Figure 15.  
When a signal is received at the MULTI-FUNCTION pin to  
disable the output through any of the MULTI-FUNCTION pin  
functions such as OV, UV and remote ON/OFF, TOPSwitch-FX  
always completes its current switching cycle as illustrated in  
Figure 7 before the output is forced off. The internal oscillator  
is stopped slightly before the end of the current cycle and  
stays there as long as the disable signal exists. When the  
signal at the MULTI-FUNCTION pin changes state from disable  
to enable, the internal oscillator starts the next switching cycle.  
This approach allows the use of this pin to synchronize  
TOPSwitch-FX to any external signal with a frequency lower  
than its internal switching frequency.  
Line Feed-Forward with DCMAX Reduction  
The same resistor used for UV and OV also implements line  
voltage feed-forward which minimizes output line ripple and  
reduces power supply output sensitivity to line transients. This  
feed-forward operation is illustrated in Figure 4 by the different  
values of IM. Note that for the same CONTROL pin current,  
higher line voltage results in smaller operating duty cycle. As  
an added safety measure, the maximum duty cycle DCMAX is  
also reduced from 78% (typical) at a voltage slightly higher  
than the UV threshold to 38% (typical) at the OV threshold (see  
Figures 4, 8). DCMAX of 38% at the OV threshold was chosen  
to ensure that the power capability of the TOPSwitch-FX is not  
restricted by this feature under normal operation.  
As seen above, the remote ON/OFF feature allows the  
TOPSwitch-FX to be turned on and off instantly, on a cycle-by-  
cycle basis, with very little delay. However, remote ON/OFF  
can also be used as a standby or power switch to turn off the  
TOPSwitch-FX and keep it in a very low power consumption  
state for indefinitely long periods. If the TOPSwitch-FX is held  
in remote off state for long enough time to allow the CONTROL  
pin to dishcharge to the internal supply undervoltage threshold  
of 4.8 V (approximately 32 ms for a 47 µF CONTROL pin  
capacitance), the CONTROL pin goes into the hysteretic mode  
of regulation. In this mode, the CONTROL pin goes through  
Time  
Figure 7. Synchronization Timing Diagram.  
7
Rev. C 06/15  
www.power.com  
TOP232-234  
alternate charge and discharge cycles between 4.8 V and  
5.8 V (see CONTROL pin operation section above) and runs  
entirely off the high-voltage DC input, but with very low power  
consumption (160 mW typical at 230 VAC with M pin open).  
When the TOPSwitch-FX is remotely turned on after entering  
this mode, it will initiate a normal start-up sequence with  
soft-start the next time the CONTROL pin reaches 5.8 V. In the  
worst case, the delay from remote on to start-up can be equal  
to the full discharge/charge cycle time of the CONTROL pin,  
which is approximately 125 ms for a 47 µF CONTROL pin  
capacitor. This reduced consumption remote off mode can  
eliminate expensive and unreliable in-line mechanical switches.  
It also allows for microprocessor controlled turn-on and  
turn-off sequences that may be required in certain applications  
such as inkjet and laser printers. See Figure 27 under  
application examples for more information.  
restart mode described above. When the fault condition is  
removed, the power supply output becomes regulated, VC  
regulation returns to shunt mode, and normal operation of the  
power supply resumes.  
Hysteretic Over-Temperature Protection  
Temperature protection is provided by a precision analog  
circuit that turns the output MOSFET off when the junction  
temperature exceeds the thermal shutdown temperature  
(135 ˚C typical). When the junction temperature cools to below  
the hysteretic temperature, normal operation resumes. A large  
hysteresis of 70 ˚C (typical) is provided to prevent overheating  
of the PC board due to a repeating fault condition. VC is  
regulated in hysteretic mode and a 4.8 V to 5.8 V (typical)  
sawtooth waveform is present on the CONTROL pin when the  
power supply is turned off.  
Bandgap Reference  
Soft-Start  
All critical TOPSwitch-FX internal voltages are derived from a  
temperature-compensated bandgap reference. This reference  
is also used to generate a temperature-compensated current  
reference which is trimmed to accurately set the switching  
frequency, MOSFET gate drive current, current limit, and the  
line OV/UV thresholds. TOPSwitch-FX has improved circuitry  
to maintain all of the above critical parameters within very tight  
absolute and temperature tolerances.  
An on-chip soft-start function is activated at start-up with a  
duration of 10 ms (typical). Maximum duty cycle starts from  
zero and linearly increases to the default maximum of 78% at  
the end of the 10 ms duration. In addition to start-up, soft-  
start is also activated at each restart attempt during auto-  
restart and when restarting after being in hysteretic regulation  
of CONTROL pin voltage (VC), due to remote off or thermal  
shutdown conditions. This effectively minimizes current and  
voltage stresses on the output MOSFET, the clamp circuit and  
the output rectifier, during start-up. This feature also helps  
minimize output overshoot and prevents saturation of the  
transformer during start-up.  
High-Voltage Bias Current Source  
This current source biases TOPSwitch-FX from the DRAIN pin  
and charges the CONTROL pin external capacitance during  
start-up or hysteretic operation. Hysteretic operation occurs  
during auto-restart, remote off and over-temperature shutdown.  
In this mode of operation, the current source is switched on  
and off with an effective duty cycle of approximately 35%.  
This duty cycle is determined by the ratio of CONTROL pin  
charge (IC) and discharge currents (ICD1 and ICD2). This current  
source is turned off during normal operation when the output  
MOSFET is switching.  
Shutdown/Auto-Restart  
To minimize TOPSwitch-FX power dissipation under fault  
conditions, the shutdown/auto-restart circuit turns the power  
supply on and off at an auto-restart duty cycle of typically 4%  
if an out of regulation condition persists. Loss of regulation  
interrupts the external current into the CONTROL pin. VC  
regulation changes from shunt mode to the hysteretic auto-  
8
Rev. C 06/15  
www.power.com  
TOP232-234  
connecting a resistor from this pin to the rectified DC high-  
voltage bus to implement OV, UV and DCMAX reduction with  
line voltage functions. In this mode, the value of the resistor  
determines the line OV/UV thresholds, and the DCMAX is  
reduced linearly with rectified DC high-voltage starting from  
just above the UV threshold. In high efficiency applications  
this pin can be used in the external current limit mode instead,  
to reduce the current limit externally to a value close to the  
operating peak current, by connecting the pin to the SOURCE  
pin through a resistor. The same pin can also be used as a  
remote on/off and a synchronization input in both modes.  
Please refer to Table 2 for possible combinations of the  
functions with example circuits shown in Figure 13 through  
Figure 23. A description of specific functions in terms of the  
MULTI-FUNCTION pin I/V characteristic is shown in Figure 8.  
The horizontal axis represents MULTI-FUNCTION pin current  
with positive polarity indicating currents flowing into the pin.  
The meaning of the vertical axes varies with functions. For  
those that control the on/off states of the output such as UV,  
OV and remote ON/OFF, the vertical axis represents the enable/  
disable states of the output. UV triggers at IUV (+50 µA typical)  
and OV triggers at IOV (+225 µA typical). Between +50 µA and  
+225 µA, the output is enabled. For external current limit and  
line feed-forward with DCMAX reduction, the vertical axis  
represents the magnitude of the ILIMIT and DCMAX. Line feed-  
forward with DCMAX reduction lowers maximum duty cycle  
from 78% at IM(DC) (+90 µA typical) to 38% at IOV (+225 µA).  
External current limit is available only with negative MULTI-  
FUNCTION pin current. Please see graphs in the typical  
performance characteristics section for the current limit program-  
ming range and the selection of appropriate resistor value.  
Using FREQUENCY and MULTI-FUNCTIONAL Pins  
FREQUENCY (F) Pin Operation  
The FREQUENCY pin is a digital input pin available in TO-220  
package only. Shorting the FREQUENCY pin to SOURCE pin  
selects the nominal switching frequency of 132 kHz (Figure 10)  
which is suited for most applications. For other cases that  
may benefit from lower switching frequency such as noise  
sensitive video applications, a 66 kHz switching frequency (half  
frequency) can be selected by shorting the FREQUENCY pin  
to the CONTROL pin (Figure 11). In addition, an example  
circuit shown in Figure 12 may be used to lower the switching  
frequency from 132 kHz in normal operation to 66 kHz in  
standby mode for very low standby power consumption.  
MULTI-FUNCTION (M) Pin Operation  
When current is fed into the MULTI-FUNCTION pin, it works as  
a voltage source of approximately 2.6 V up to a maximum  
current of +400 µA (typical). At +400 µA, this pin turns into a  
constant current sink. When current is drawn out of the  
MULTI-FUNCTION pin, it works as a voltage source of  
approximately 1.32 V up to a maximum current of –240 µA  
(typical). At –240 µA, it turns into a constant current source.  
Refer to Figure 9.  
There are a total of five functions available through the use of  
the MULTI-FUNCTION pin: OV, UV, line feed-forward with  
DCMAX reduction, external current limit and remote ON/OFF. A  
short circuit between the MULTI-FUNCTION pin and SOURCE  
pin disables all five functions and forces TOPSwitch-FX to  
operate in a simple three terminal mode like TOPSwitch-II. The  
MULTI-FUNCTION pin is typically used for line sensing by  
MULTI-FUNCTION PIN TABLE*  
13  
14  
15  
16  
17  
18  
19  
20  
21  
22  
23  
Figure Number ꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀ  
4
Three Terminal Operation  
Undervoltage  
4
4
4
4
4
4
4
Overvoltage  
4
Line Feed-forward (DCMAX  
)
Line Feed-forward (ILIMIT  
External Current Limit  
Remote ON/OFF  
)
4ꢀ  
4
4
4
4
4
4
4
4
4
*This table is only a partial list of many MULTI-FUNCTION pin configurations that are possible.  
Table 2. Typical MULTI-FUNCTION Pin Configurations.  
9
Rev. C 06/15  
www.power.com  
TOP232-234  
IREM(N)  
IUV  
IOV  
(Enabled)  
Output  
MOSFET  
Switching  
(Disabled)  
Disabled when supply  
output goes out of  
regulation  
IM  
ILIMIT (Default)  
Current  
Limit  
IM  
DCMAX (78.5%)  
Maximum  
Duty Cycle  
IM  
VBG + VTP  
MULTI-  
FUNCTION  
Pin Voltage  
VBG  
IM  
-250  
-200  
-150  
-100  
-50  
0
50  
100  
150  
200  
250  
300  
350  
400  
MULTI-FUNCTION Pin Current (µA)  
Note: This figure provides idealized functional characteristics of the MULTI-FUNCTION pin with typical performance values.  
Please refer to the parametric table and typical performance characteristics sections of the data sheet for measured data.  
PI-2524-081999  
Figure 8. MULTI-FUNCTION Pin Characteristics.  
CONTROL Pin  
TOPSwitch-FX  
240 µA  
(Negative Current Sense - ON/OFF,  
Current Limit Adjustment)  
VBG + VT  
MULTI-FUNCTION Pin  
VBG  
(Positive Current Sense - Undervoltage,  
Overvoltage, Maximum Duty  
Cycle Reduction)  
400 µA  
PI-2548-062515  
Figure 9. MULTI-FUNCTION Pin Input Simplified Schematic.  
10  
Rev. C 06/15  
www.power.com  
TOP232-234  
Typical Uses of FREQUENCY (F) Pin  
+
+
DC  
Input  
Voltage  
DC  
Input  
D
S
D
CONTROL  
CONTROL  
Voltage  
C
C
F
S
F
-
-
PI-2506-081199  
PI-2505-081199  
Figure 11. Half Frequency Operation (66 kHz).  
Figure 10. Full Frequency Operation (132 kHz).  
+
QS can be an optocoupler output.  
DC  
Input  
Voltage  
D
S
CONTROL  
C
STANDBY  
F
47 kΩ  
QS  
1 nF  
20 kΩ  
RHF  
-
PI-2507-040401  
Figure 12. Half Frequency Standby Mode (For High Standby Efficiency).  
11  
Rev. C 06/15  
www.power.com  
TOP232-234  
Typical Uses of MULTI-FUNCTION (M) Pin  
+
+
VUV = IUV x RLS  
VOV = IOV x RLS  
For RLS = 2 MΩ  
VUV = 100 VDC  
VOV = 450 VDC  
RLS  
2 MΩ  
DC  
Input  
DC  
Input  
Voltage  
Voltage  
DCMAX@100 VDC = 78%  
DCMAX@375 VDC = 47%  
D
S
M
D
S
M
CONTROL  
CONTROL  
C
C
-
-
PI-2508-081199  
PI-2509-040401  
Figure 13. Three Terminal Operation (MULTI-FUNCTION Features Disabled.  
FREQUENCY Pin Tied to SOURCE or CONTROL Pin).  
Figure 14. Line Sensing for Undervoltage, Overvoltage and Maximum Duty  
Cycle Reduction.  
+
+
VUV = RLS x IUV  
2 MΩ  
VOV = IOV x RLS  
2 MΩ  
For Value Shown  
VUV = 100 VDC  
For Values Shown  
VOV = 450 VDC  
RLS  
RLS  
DC  
Input  
DC  
Input  
22 kΩ  
30 kΩ  
IN4148  
Voltage  
Voltage  
D
S
M
D
S
M
CONTROL  
CONTROL  
C
C
6.2 V  
-
-
PI-2510-040401  
PI-2516-040401  
Figure 15. Line Sensing for Undervoltage Only (Overvoltage Disabled).  
Figure 16. Line Sensing for Overvoltage Only (Undervoltage Disabled).  
+
+
For RIL = 12 kΩ  
ILIMIT = 90% @ 100 VDC  
ILIMIT = 67%  
ILIMIT  
=
55% @ 300 VDC  
RLS  
2.5 MΩ  
For RIL = 25 kΩ  
ILIMIT = 40%  
DC  
Input  
Voltage  
DC  
See graph for other  
Input  
resistor values (RIL)  
Voltage  
D
S
M
D
M
CONTROL  
CONTROL  
RIL  
6 kΩ  
C
C
RIL  
S
-
-
PI-2518-040401  
PI-2517-040401  
Figure 18. Current Limit Reduction with Line Voltage.  
Figure 17. Externally Set Current Limit.  
12  
Rev. C 06/15  
www.power.com  
TOP232-234  
Typical Uses of MULTI-FUNCTION (M) Pin (cont.)  
+
+
QR can be an optocoupler  
output or can be replaced  
by a manual switch.  
QR can be an optocoupler  
output or can be replaced by  
a manual switch.  
QR  
DC  
Input  
Voltage  
DC  
Input  
Voltage  
ON/OFF  
RMC  
47 kΩ  
45 kΩ  
D
S
M
D
M
CONTROL  
CONTROL  
C
QR  
C
ON/OFF  
47 kΩ  
-
S
-
PI-2519-040401  
PI-2522-040401  
Figure 19. Active-on (Fail Safe) Remote ON/OFF.  
Figure 20. Active-Off Remote ON/OFF.  
+
+
QR can be an optocoupler  
output or can be replaced  
by a manual switch.  
QR can be an optocoupler  
output or can be replaced  
by a manual switch.  
QR  
For RIL = 12 kΩ  
ILIMIT = 67 %  
ON/OFF  
DC  
Input  
DC  
Input  
Voltage  
47 kΩ  
For RIL = 25 kΩ  
ILIMIT = 40 %  
Voltage  
RMC  
24 kΩ  
RMC = 2RIL  
D
S
M
RIL  
QR  
D
S
M
CONTROL  
CONTROL  
C
RIL  
C
12 kΩ  
ON/OFF  
47 kΩ  
-
-
PI-2520-040401  
PI-2521-040401  
Figure 21. Active-on Remote ON/OFF with Externally Set Current Limit.  
Figure 22. Active-off Remote ON/OFF with Externally Set Current Limit.  
QR can be an optocoupler  
output or can be replaced  
by a manual switch.  
+
RLS  
2 M  
QR  
DC  
Input  
ON/OFF  
47 kΩ  
For RLS = 2 MΩ  
Voltage  
D
M
VUV = 100 VDC  
VOV = 450 VDC  
CONTROL  
C
S
-
PI-2523-062915  
Figure 23. Active-off Remote ON/OFF with Line Sense.  
13  
Rev. C 06/15  
www.power.com  
TOP232-234  
TOPSwitch-FX drain voltage, with adequate margin, under  
worst case conditions. The extended maximum duty cycle  
feature of TOPSwitch-FX (guaranteed minimum value of 75%  
vs. 64% for TOPSwitch-II) allows the use of a smaller input  
capacitor (C1). The extended maximum duty cycle and the  
higher reflected voltage possible with the RCD clamp also  
permit the use of a higher primary to secondary turns ratio for  
T1 which reduces the peak reverse voltage experienced by the  
secondary rectifier D8. As a result, a 60 V Schottky rectifier  
can be used for up to 15 V outputs, which greatly improves  
power supply efficiency. The cycle skipping feature of the  
TOPSwitch-FX eliminates the need for any dummy loading for  
regulation at no load and reduces the no load/standby  
consumption of the power supply. Frequency jitter provides  
improved margin for conducted EMI meeting the CISPR 22  
(FCC B) specification.  
Application Examples  
A High Efficiency, 30 W, Universal Input Power Supply  
The circuit shown in Figure 24 takes advantage of several of  
the TOPSwitch-FX features to reduce system cost and power  
supply size and to improve efficiency. This design delivers 30 W  
at 12 V, from an 85 to 265 VAC input, at an ambient of 50 ˚C,  
in an open frame configuration. A nominal efficiency of 80% at  
full load is achieved using TOP234.  
The current limit is externally set by resistors R1 and R2 to a  
value just above the low line operating peak current of  
approximately 70% of the default current limit. This allows use  
of a smaller transformer core size and/or higher transformer  
primary inductance for a given output power, reducing  
TOPSwitch-FX power dissipation, while at the same time  
avoiding transformer core saturation during startup and output  
transient conditions. The resistor R1 provides a feed-forward  
signal that reduces the current limit with increasing line  
voltage, which, in turn, limits the maximum overload power at  
high input line voltage. The feed-forward function in  
A simple Zener sense circuit is used for low cost. The output  
voltage is determined by the Zener diode (VR2) voltage and  
the voltage drops across the optocoupler (U2) LED and  
resistor R6. Resistor R8 provides bias current to Zener VR2 for  
typical regulation of 5% at the 12 V output level, over line and  
load and component variations.  
combination with the built-in soft-start feature of TOPSwitch-  
FX, allows the use of a low cost RCD clamp (R3, C3 and D1)  
with a higher reflected voltage, by safely limiting the  
CY1  
2.2 nF  
C14 R15  
1 nF 150  
L3  
3.3 µH  
12 V  
@ 2.5 A  
R3  
68 kΩ  
2W  
C3  
4.7 nF  
1KV  
C12  
220 µF  
35 V  
D8  
MBR1060  
C10  
560 µF  
35 V  
C11  
560 µF  
35 V  
BR1  
600 V  
2A  
RTN  
D1  
UF4005  
R1  
D2  
1N4148  
4.7 MΩ  
1/2 W  
R6  
150 Ω  
L1  
20 mH  
R8  
150 Ω  
T1  
C6  
100 nF  
U2  
C1  
68 µF  
400 V  
LTV817A  
CX1  
TOPSwitch-FX  
U1  
D
S
M
100 nF  
TOP234Y  
250 VAC  
CONTROL  
C
R5  
6.8 Ω  
F1  
3.15 A  
R2  
9.09 kΩ  
F
VR2  
1N5240C  
10 V, 2%  
J1  
L
C5  
47 µF  
10 V  
N
PI-2525-062515  
Figure 24. 30 W Power Supply using External Current Limit.  
14  
Rev. C 06/15  
www.power.com  
TOP232-234  
CONTROL pin instead of the SOURCE pin in video noise  
sensitive applications to allow for heavier snubbing without  
significant impact on efficiency.  
35 W Multiple Output Power Supply  
Figure 25 shows a five output, 35 W, secondary regulated  
power supply utilizing a TOP233 for multiple output applications  
such as set-top box, VCR, DVD, etc. The circuit shown is  
designed for a 230 VAC input but can be used over the  
universal range at a derated output power of 25 W. Alternatively,  
a doubler input stage can be used at 100 or 115 VAC for the  
full power rating of 35 W. TOPSwitch-FX provides several  
advantages in the above mentioned applications.  
This design achieves 5% load regulation on 3.3 V and 5 V  
outputs using dual sensed optocoupler feedback through  
resistors R9, R10 and R11. Other output voltages are set by  
the transformer turns ratio. Output voltage on the low power  
-5 V output is shunt regulated by resistor R12 and Zener diode  
VR2. Dummy load resistor R13 is required to maintain  
regulation of the 30 V output under light load conditions.  
Compensation of the TL431 (U3) is achieved with resistor R8  
and capacitor C7. Primary side compensation and auto-  
restart frequency are determined by resistor R5 and capacitor  
C5. Second stage LC post-filtering is used on the 3.3 V, 5 V  
and 18 V high power outputs (L2, L3, L4 and C13, C15, C17)  
for low ripple. Full load operating efficiency exceeds 75%  
across the AC input range. Primary clamp components VR1  
and D1 limit peak drain voltage to a safe value.  
A single line sense resistor R1 (2 M) implements an under-  
voltage detect (at 100 V), overvoltage shutdown (at 450 V) and  
line feed-forward with DCMAX reduction features. Under-  
voltage detect ensures that the outputs are glitch free on  
power down. The over-voltage shutdown turns off the  
TOPSwitch-FX MOSFET above 450 V on the DC input rail,  
eliminating reflected voltage and leakage inductance spikes,  
and hence, extending the surge withstand to the 700 VDC  
rating of the MOSFET. This feature prevents field failures in  
countries where prolonged line voltage surges are common.  
The frequency jittering in TOPSwitch-FX helps reduce EMI,  
maintaining emissions below CISPR 22 (FCC B) levels through  
proper choice of Y1 capacitor (CY1) and input filtering elements  
(CX1, L1). To minimize coupling of common mode transients to  
the TOP233, Y1 capacitor is tied to the positive input DC rail.  
Lightning strike immunity to 3 kV is attained with the addition  
of a 275 V MOV (RV1).  
This design also takes advantage of soft-start and higher  
operating frequency to reduce transformer size. A snubber  
circuit (R4, C4) is used to slowdown dv/dt of the switching  
waveform minimizing radiated video noise that could interfere  
with TV reception. The half frequency option of the TOPSwitch-FX  
can be used by connecting the FREQUENCY pin to the  
30 V  
@ 100 mA  
C11  
D8  
MUR120  
C10  
1 µF  
L2  
3.3 µH  
100 µF  
18 V  
@ 550 mA  
50 V  
50 V  
C12  
220 µF  
25 V  
C13  
100 µF  
25 V  
D9  
CY1  
2.2 nF  
R13  
UF5402  
L3  
3.3 µH  
24 kΩ  
5 V  
@ 2.5 A  
D10  
MBR1045  
C14  
C15  
100 µF  
10 V  
1000 µF  
L4  
3.3 V  
@ 3 A  
25 V  
3.3 µH  
VR1  
P6KE200  
D11  
BYW29-  
100  
C16  
C17  
100 µF  
10 V  
1000 µF  
25 V  
D1  
UF4007  
RTN  
BR1  
400 V  
C18  
C19  
330 µF  
VR2  
1N5231  
100 µF  
D12  
1N5819  
R12  
5 Ω  
-5 V  
@ 100 mA  
10 V  
10 V  
C1  
33 µF  
400 V  
L1  
20 mH  
D2  
1N4148  
R6  
51 Ω  
R1  
2 MΩ  
1/2 W  
R10  
15.0 kΩ  
T1  
U2  
LTV817  
R7  
CX1  
0.1 µF  
510 Ω  
C6  
100 nF  
R9  
9.53 kΩ  
TOPSwitch-FX  
U1  
250 VAC  
D
S
M
C4  
TOP233Y  
47 pF  
CONTROL  
C7  
R8  
F1  
C
10 0.1 µF  
3.15 A  
R4  
2 kΩ  
R5  
6.8 Ω  
F
J1  
L
U3  
TL431CLP  
C5  
47 µF  
C8  
22 µF  
RV1  
275 V  
R11  
10.0 kΩ  
N
PI-2536-062515  
Figure 25. 35 W Set-Top Box Power Supply.  
1ꢀ  
Rev. C 06/15  
www.power.com  
TOP232-234  
17 W PC Standby Power Supply  
This is achieved by turning the power supply off when the  
input voltage goes below a level needed to maintain output  
regulation and keeping it off until the input voltage goes above  
the under-voltage threshold (VUV), when the AC is turned on  
again. The under voltage threshold is set at 200 VDC, slightly  
below the required lowest operating DC input voltage, for  
start-up at 170 VAC. This feature saves several components  
needed to implement the glitch free turn off with discrete or  
TOPSwitch-II based designs.  
Figure 26 shows a 17 W PC standby application with 3.3 V  
and 5 V secondary outputs and a 15 V primary output. The  
supply uses the TOP232 operating from 230 VAC or 100/  
115 VAC with doubler input. This design takes advantage of  
the soft-start, line under-voltage detect, tighter current limit  
variation and higher switching frequency features of  
TOPSwitch-FX. For example, the higher switching frequency  
with tighter current limit variation allows use of an EE19  
transformer core. Furthermore, the spacing between high-  
voltage DRAIN pin and low voltage pins of the TOPSwitch-FX  
packages provides large creepage distance which is a  
significant advantage in high pollution environments such as  
fan cooled PC power supplies.  
The bias winding is rectified and filtered by D2 and C6 to  
create a bias voltage for the TOP232 and to provide a 15 V  
primary bias output voltage for the main power supply primary  
control circuitry. Both 3.3 V and 5 V output voltages are  
sensed by R9, R10 and R11 using a TL431 (U3) circuit shown.  
Resistor R6 limits current through optocoupler U2 and sets  
overall AC control loop gain. Resistor R7 assures that there is  
sufficient bias current for the TL431 when the optocoupler is at  
a minimum current. Capacitor C8 provides a soft-finish  
function to eliminate turn-on overshoot. The no load regulation  
(cycle-skipping) of TOPSwitch-FX permits the circuit to meet  
the low standby power requirement of the Blue Angel  
specification for PCs.  
Capacitor C1 provides high frequency decoupling of the  
high-voltage DC supply, and is necessary only if there is a long  
trace length from the source of the DC supply to the inputs of  
this standby circuit. The line sense resistor R1 senses the DC  
input voltage for line undervoltage. When AC is turned off, the  
under-voltage detect feature of the TOPSwitch-FX prevents  
auto-restart glitches at the output caused by the slow  
discharge of large storage capacitance in the main converter.  
CY1  
1 nF  
L1  
3.3 µH  
5 V  
@ 2 A  
C10  
C11  
100 µF  
10 V  
D3  
L2  
3.3 µH  
1000 µF  
3.3 V  
+
SB540  
10 V  
@ 2 A  
VR1  
BZY97C-  
200  
C12  
1000 µF  
10 V  
C13  
100 µF  
10 V  
D4  
SB540  
RTN  
200 - 375  
VDC  
R1  
3.9 MΩ  
15 V  
D1  
UF4005  
@ 30 mA  
D2  
BAV21  
R6  
301 Ω  
(Primary  
Referenced)  
C1  
R9  
16.2 kΩ  
R7  
510 Ω  
T1  
0.01 µF  
1 kV  
(optional)  
C6  
35 V  
U2  
SFH615-2  
TOPSwitch-FX  
U1  
TOP232Y  
C
D
S
M
R10  
12.1 kΩ  
CONTROL  
C7  
0.1 µF  
R5  
6.8 Ω  
F
C8  
U3  
TL431CLP  
10 µF  
R11  
10 kΩ  
C5  
47 µF  
35 V  
PI-2537-062515  
Figure 26. 17 W PC Standby Supply.  
16  
Rev. C 06/15  
www.power.com  
TOP232-234  
Processor Controlled Supply Turn On/Off  
In the case of products with a disk drive, the shutdown  
procedure may include saving data or settings to the disk.  
After the shutdown procedure is complete, when it is safe to  
turn off the power supply, the microprocessor releases the  
M pin by turning the optocoupler U4 off. If the manual switch  
and the optocouplers U3 and U4 are not located close to the  
M pin, a capacitor CM may be needed to prevent noise  
coupling to the pin when it is open.  
A low cost momentary contact switch can be used to turn the  
TOPSwitch-FX power on and off under microprocessor control  
that may be required in some applications such as printers.  
The low power remote off feature allows an elegant implemen-  
tation of this function with very few external components as  
shown in Figure 27. Whenever the push button momentary  
contact switch P1 is closed by the user, the optocoupler U3 is  
activated to inform the microprocessor of this action. Initially,  
when the power supply is off (M pin is floating), closing of P1  
turns the power supply on by shorting the M pin of the  
TOPSwitch-FX to SOURCE through a diode (remote on). When  
the secondary output voltage VCC is established, the micro-  
processor comes alive and recognizes that the switch P1 is  
closed through the switch status input that is driven by the  
optocoupler U3 output. The microprocessor then sends a  
power supply control signal to hold the power supply in the  
on-state through the optocoupler U4. If the user presses the  
switch P1 again to command a turn off, the microprocessor  
detects this through the optocoupler U3 and initiates a  
shutdown procedure that is product specific. For example, in  
the case of the inkjet printer, the shutdown procedure may  
include safely parking the print heads in the storage position.  
The power supply could also be turned on remotely through a  
local area network or a parallel or serial port by driving the  
optocoupler U4 input LED with a logic signal. Sometimes it is  
easier to send a train of logic pulses through a cable (due to  
AC coupling of cable, for example) instead of a DC logic level  
as a wake-up signal. In this case, a simple RC filter can be  
used to generate a DC level to drive U4 (not shown in Figure  
27). This remote on feature can be used to wake-up  
peripherals such as printers, scanners, external modems, disk  
drives, etc., as needed from a computer. Peripherals are  
usually designed to turn off automatically if they are not being  
used for a period of time, to save power.  
VCC  
(+5 V)  
+
External  
Wake-up  
Signal  
High-Voltage  
DC Input  
Power  
Supply  
ON/OFF  
Control  
MICRO-  
PROCESSOR/  
CONTROLLER  
100 k  
27 kΩ  
U2  
1N4148  
LOGIC LOGIC  
INPUT OUTPUT  
1N4148  
6.8 kΩ  
TOPSwitch-FX  
C
D
S
M
U3  
U4  
CONTROL  
6.8 kΩ  
CM  
1 nF  
47 µF  
F
U4  
LTV817A  
U1  
U3  
LTV817A  
P1  
P1 Switch  
Status  
RETURN  
PI-2561-062615  
Figure 27. Remote ON/OFF using Microcontroller.  
17  
Rev. C 06/15  
www.power.com  
TOP232-234  
In addition to using a minimum number of components,  
TOPSwitch-FX provides many technical advantages in this  
type of application:  
shutdown sequence when it detects the first closure of the  
switch, and subsequent bouncing of the switch has no  
effect. If necessary, the microprocessor could implement  
the switch debouncing in software during turn-off, or a filter  
capacitor can be used at the switch status input.  
4. No external current limiting circuitry is needed for the  
operation of the U4 optocoupler output due to internal  
limiting of M pin current.  
5. No high-voltage resistors to the input DC voltage rail are  
required to power the external circuitry in the primary. Even  
the LED current for U3 can be derived from the CONTROL  
pin. This not only saves components and simplifies layout,  
but also eliminates the power loss associated with the  
high-voltage resistors in both on and off states.  
1. Extremely low power consumption in the off mode: 80 mW  
typical at 110 VAC and 160 mW typical at 230 VAC. This is  
because in the remote/off mode the TOPSwitch-FX  
consumes very little power, and the external circuitry does  
not consume any current (M pin is open) from the high-  
voltage DC input.  
2. A very low cost, low voltage/current, momentary contact  
switch can be used.  
3. No debouncing circuitry for the momentary switch is  
required. During turn-on, the start-up time of the power  
supply (typically 10 to 20 ms) plus the microprocessor  
initiation time act as a debouncing filter, allowing a turn-on  
only if the switch is depressed firmly for at least the above  
delay time. During turn-off, the microprocessor initiates the  
6. Robust design: There is no on/off latch that can be  
accidentally triggered by transients. Instead, the power  
supply is held in the on-state through the secondary side  
microprocessor.  
18  
Rev. C 06/15  
www.power.com  
TOP232-234  
Key Application Considerations  
TOPSwitch-FX vs. TOPSwitch-ll  
Table 3 compares the features and performance differences  
between TOPSwitch-FX and TOPSwitch-II. Many of the new  
features eliminate the need for costly discrete component.  
Other features increase the robustness of design allowing  
cost savings in the transformer and other power components.  
Function  
TOPSwitch-II  
TOPSwitch-FX  
Figures Advantages  
Soft-Start  
N/A*  
10 ms  
• Limits peak current and voltage  
component stresses during start-up  
• Eliminates external components  
used for soft-start in most applications  
• Minimizes output overshoot  
External Current Limit  
N/A*  
67%  
Programmable  
100% to 40% of  
default current  
limit  
8, 17,  
18, 21,  
22  
• Smaller transformer  
• Higher efficiency  
• Allows tighter power limit  
during output overload conditions  
DCMAX  
78%  
4
• Smaller input cap (wider dynamic range)  
• Higher power capability (when used  
with RCD clamp for large VOR)  
• Allows use of Schottky secondary  
rectifier diode for up to 15 V output  
for high efficiency  
Line Feed-forward with  
DCMAX Reduction  
N/A*  
78% to 38%  
4, 8, 14, • Rejects line ripple  
23  
• Increases transient and surge voltage  
withstand capability  
Line OV Shutdown  
Line UV Detection  
Switching Frequency  
N/A*  
Single resistor  
programmable  
8, 14,  
16, 23  
• Increases voltage withstand capability  
against line surge  
N/A*  
Single resistor  
programmable  
5, 8, 14, • Prevents auto-restart glitches during  
15, 23  
power-down  
100 kHz 10%  
132 kHz 7%  
10  
• Smaller transformer  
• Fundamental below 150 kHz for  
conducted EMI  
Switching Frequency  
Option (TO-220 only)  
N/A*  
66 kHz 7%  
11, 12  
• Lower losses when using RC and RCD  
snubber for noise reduction in video  
applications  
• Allows for higher efficiency in standby  
mode  
• Lower EMI (second harmonic below  
150 kHz)  
Frequency Jitter  
Cycle Skipping  
N/A*  
N/A*  
4 kHz@132 kHz  
2 kHz@66 kHz  
6, 28  
4
• Reduces conducted EMI  
At DCMIN (1.5%)  
• Zero load regulation without dummy  
load  
• Low power consumption at no load  
*Not available  
Table 3. Comparison Between TOPSwitch-II and TOPSwitch-FX. (continued on next page)  
19  
Rev. C 06/15  
www.power.com  
TOP232-234  
Function  
TOPSwitch-II  
TOPSwitch-FX  
Figures Advantages  
Remote ON/OFF  
N/A*  
Single transistor  
or optocoupler  
interface or manual  
switch  
8, 19,  
20, 21,  
• Fast on/off (cycle by cycle)  
• Active-on or active-off control  
22, 23, • Low consumption in remote off state  
27  
• Active-on control for fail-safe  
• Eliminates expensive in-line on/off  
switch  
• Allows processor controlled turn on/off  
• Permits shutdown/wake-up of  
peripherals via LAN or parallel port  
Synchronization  
N/A*  
Single transistor  
or optocoupler  
interface  
• Synchronization to external lower  
frequency signal  
• Starts new switching cycle on demand  
Thermal Shutdown  
Current Limit Tolerance  
Latched  
10% (@25 °C)  
Hysteretic (with  
70 °C hysteresis)  
• Automatic recovery from thermal fault  
• Large hysteresis prevents circuit  
board overheating  
7% (@25 °C)  
• 10% higher power capability due to  
tighter tolerance  
-8% (0 °C to100 °C) -4% (0 °C to 100 °C)  
DRAIN  
DIP  
0.037” / 0.94 mm  
0.037” / 0.94 mm  
0.137” / 3.48 mm  
0.137” / 3.48 mm  
0.068” / 1.73 mm  
• Greater immunity to arcing as a  
result of build-up of dust, debris and  
other contaminants  
Creepage at  
Package  
SMD  
TO-220 0.046” / 1.17 mm  
0.045” / 1.14 mm  
DRAIN Creepage at  
PCB for TO-220  
0.113” / 2.87 mm  
(preformed leads)  
• Preformed leads accommodate  
large creepage for PCB layout  
• Easier to meet Safety (UL/VDE)  
*Not available  
Table 3 (cont). Comparison Between TOPSwitch-II and TOPSwitch-FX.  
Primary Clamp and Output Reflected Voltage VOR  
A primary clamp is necessary to limit the peak TOPSwitch-FX  
drain to source voltage. A Zener clamp (see Figure 26, VR1)  
requires few parts and takes up little board space. For good  
efficiency, the clamp Zener should be selected to be at least  
1.5 times the output reflected voltage VOR as this keeps the  
leakage spike conduction time short. When using a Zener  
clamp in a universal input application, a VOR of less than 135 V  
is recommended to allow for the absolute tolerances and  
temperature variations of the Zener. This will ensure efficient  
operation of the clamp circuit and will also keep the maximum  
drain voltage below the rated breakdown voltage of the  
TOPSwitch-FX MOSFET.  
TOPSwitch-FX Design Considerations  
TOPSwitch-FX Selection  
Selecting the optimum TOPSwitch-FX depends upon required  
maximum output power, efficiency, heat sinking constraints  
and cost goals. With the option to externally reduce current  
limit, a larger TOPSwitch-FX may be used for lower power  
applications where higher efficiency is needed or minimal heat  
sinking is available.  
Input Capacitor  
The input capacitor must be chosen to provide the minimum  
DC voltage required for the TOPSwitch-FX converter to  
maintain regulation at the lowest specified input voltage and  
maximum output power. Since TOPSwitch-FX has a higher  
DCMAX than TOPSwitch-II, it is possible to use a smaller input  
capacitor. For TOPSwitch-FX, a capacitance of 2 µF per watt  
is usually sufficient for universal input with an appropriately  
designed transformer.  
A high VOR is required to take full advantage of the wider DCMAX  
of TOPSwitch-FX. An RCD clamp provides tighter clamp  
voltage tolerance than a Zener clamp and allows a VOR as high  
as 165 V. The VOR can be further increased in continuous  
mode designs up to 185 V by reducing the external current  
limit as a function of input line voltage (see Figure 18). The  
RCD clamp is more cost effective than the Zener clamp but  
requires more careful design (see quick design checklist).  
20  
Rev. C 06/15  
www.power.com  
TOP232-234  
Output Diode  
The output diode is selected for peak inverse voltage, output  
current, and thermal conditions in the application (including  
heat sinking, air circulation, etc.). The higher DCMAX of  
TOPSwitch-FX along with an appropriate transformer turns  
ratio can allow the use of a 60 V Schoktty diode for higher  
efficiency on output voltages as high as 15 V (See Figure 24.  
A 12 V, 30 W design using a 60 V Schottky for the output  
diode).  
Average  
Soft-Start  
Quasi-Peak  
Generally a power supply experiences maximum stress at  
start-up before the feedback loop achieves regulation. For a  
period of 10 ms the on-chip soft-start linearly increases the  
duty cycle from zero to the default DCMAX at turn on, which  
causes the primary current and output voltage to rise in an  
orderly manner allowing time for the feedback loop to take  
control of the duty cycle. This reduces the stress on the  
TOPSwitch-FX MOSFET, clamp circuit and output diode(s),  
and helps prevent transformer saturation during start-up. Also,  
soft-start limits the amount of output voltage overshoot, and in  
many applications eliminates the need for a soft-finish  
capacitor.  
Switching Harmonic  
(a)  
80  
70  
60  
50  
40  
30  
TOPSwitch-II (no jitter)  
EMI  
The frequency jitter feature modulates the switching frequency  
over a narrow band as a means to reduce conducted EMI  
peaks associated with the harmonics of the fundamental  
switching frequency. This is particularly beneficial for average  
detection mode. As can be seen in Figure 28, the benefits of  
jitter increase with the order of the switching harmonic due to  
an increase in frequency deviation.  
20  
-10  
0
VFG243B (QP)  
VF646B (AV)  
-10  
-20  
The FREQUENCY pin of TOPSwitch-FX offers a switching  
frequency option of 132 kHz or 66 kHz. In applications that  
require heavy snubbers on the drain node for reducing high  
frequency radiated noise (for example, video noise sensitive  
applications such as VCR, DVD, monitor, TV, etc.), operating at  
66 kHz will reduce snubber loss resulting in better efficiency.  
Also, in applications where transformer size is not a concern,  
use of the 66 kHz option will provide lower EMI and higher  
efficiency. Note that the second harmonic of 66 kHz is still  
below 150 kHz, above which the conducted EMI specifications  
get much tighter.  
0.15  
1
10  
30  
Frequency (MHz)  
(b)  
80  
70  
60  
TOPSwitch-FX (with jitter)  
50  
40  
30  
20  
-10  
0
For 10 W or below, it is possible to use a simple inductor in  
place of a more costly AC input common mode choke to meet  
worldwide conducted EMI limits.  
Transformer Design  
It is recommended that the transformer be designed for  
maximum operating flux density of 3000 gauss and a peak  
flux density of 4200 gauss at maximum current limit. The  
turns ratio should be chosen for a reflected voltage (VOR) no  
greater than 135 V when  
VFG243B (QP)  
VF646B (AV)  
-10  
-20  
0.15  
1
10  
30  
Frequency (MHz)  
(c)  
Figure 28. (a) Conducted Noise Improvement for Low Frequency  
Harmonics due to Jitter, (b) TOPSwitch-II Full Range EMI Scan  
(100 kHz, no Jitter), (c) TOPSwitch-FX Full Range EMI Scan  
(132 kHz, with Jitter) with Identical Circuitry and Conditions.  
21  
Rev. C 06/15  
www.power.com  
TOP232-234  
Maximize hatched copper  
areas (  
heat sinking  
) for optimum  
Safety Spacing  
Y1-  
Capacitor  
+
Output Filter Capacitor  
J1  
Input Filter Capacitor  
HV  
T
r
PRI  
SEC  
a
n
s
f
S
S
D
o
r
m
e
r
BIAS  
TOPSwitch-FX  
TOP VIEW  
M
S
S
C
Opto-  
coupler  
R1  
DC  
Out  
+
PI-2543-062615  
Figure 29. Layout Considerations for TOPSwitch-FX using DIP or SMD (Using Line Sensing for Under-Voltage and Overvoltage).  
Maximize hatched copper  
areas (  
) for optimum  
Safety Spacing  
heat sinking  
Y1-  
Capacitor  
+
Output Filter Capacitor  
J1  
Input Filter Capacitor  
HV  
T
r
a
n
s
f
o
r
m
e
r
PRI  
SEC  
D
C
F
BIAS  
S
R1  
M
Heat Sink  
R2  
TOPSwitch-FX  
TOP VIEW  
Opto-  
coupler  
DC  
Out  
+
PI-2544-062615  
Figure 30. Layout Considerations for TOPSwitch-FX using TO-220 Package (Using Current Limit Reduction with Line Voltage).  
22  
Rev. C 06/15  
www.power.com  
TOP232-234  
using a Zener clamp, 165 V when using an RCD clamp and  
185 V when using RCD clamp with current limit feed-forward.  
When using P (DIP-8) or G (SMD-8) packages, a copper area  
underneath the package connected to the SOURCE pins will  
act as an effective heat sink.  
For designs where operating current is significantly lower than  
the default current limit, it is recommended to use an externally  
set current limit close to the operating peak current to reduce  
peak flux density and peak power (see Figure 17). In most  
applications, the tighter current limit tolerance, higher switching  
frequency and soft-start features of TOPSwitch-FX contribute  
to a smaller transformer when compared to TOPSwitch-II.  
In addition, sufficient copper area should be provided at the  
anode and cathode leads of the output diode(s) for heat  
sinking.  
Quick Design Checklist  
As with any power supply design, all TOPSwitch-FX designs  
should be verified on the bench to make sure that components  
specifications are not exceeded under worst case conditions.  
The following minimum set of tests is strongly recommended:  
1. Maximum drain voltage – Verify that peak VDS does not  
exceed 675 V at highest input voltage and maximum  
overload output power. Maximum overload output power  
occurs when the ouput is overloaded to a level just before  
the power supply goes into auto-restart (loss of regulation).  
2. Maximum drain current – At maximum ambient  
temperature, maximum input voltage and maximum output  
load, verify drain current waveforms at start-up for any  
signs of transformer saturation and excessive leading edge  
current spikes. TOPSwitch-FX has a leading edge blanking  
time of 200 ns to prevent premature termination of the  
on-cycle. Verify that the leading edge current spike is  
below the allowed current limit envelope (see Figure 33) for  
the drain current waveform at the end of the 200 ns  
blanking period.  
3. Thermal check – At maximum output power, minimum  
input voltage and maximum ambient temperature, verify  
that temperature specifications are not exceeded for  
TOPSwitch-FX, transformer, output diodes and output  
capacitors. Enough thermal margin should be allowed for  
the part-to-part variation of the RDS(ON) of TOPSwitch-FX as  
specified in the data sheet. The margin required can either  
be calculated from the tolerances or it can be accounted  
for by connecting an external resistance in series with the  
DRAIN pin and attached to the same heat sink, having a  
resistance value that is equal to the difference between the  
measured RDS(ON) of the device under test and the worst  
case maximum specification.  
Standby Consumption  
Cycle skipping can significantly reduce power loss at zero  
load, especially when a Zener clamp is used. For very low  
secondary power consumption use a TL431 regulator for  
feedback control. Alternately, switching losses can be  
significantly reduced by switching from 132 kHz in normal  
operation to 66 kHz under light load conditions.  
TOPSwitch-FX Layout Considerations  
Primary Side Connections  
Use a single point (Kelvin) connection at the negative terminal  
of the input filter capacitor for TOPSwitch-FX SOURCE pin and  
bias winding return. This improves surge capabilities by  
returning surge currents from the bias winding directly to the  
input filter capacitor.  
The CONTROL pin bypass capacitor should be located as  
close as possible to the SOURCE and CONTROL pins and its  
SOURCE connection trace should not be shared by the main  
MOSFET switching currents.  
All SOURCE pin referenced components connected to the  
MULTI-FUNCTION pin should also be located close to  
SOURCE and MULTI-FUNCTION pins with dedicated  
SOURCE pin connection. The MULTI-FUNCTION pin’s trace  
should be kept as short as possible and away from the DRAIN  
trace to prevent noise coupling. Line sense resistor (R1 in  
Figures 29 and 30) should be located close to the MULTI-  
FUNCTION pin to minimize the trace length on the MULTI-  
FUNCTION pin side.  
Design Tools  
In addition to the 47 µF CONTROL pin capacitor, a high  
frequency bypass capacitor in parallel may be used for better  
noise immunity. The feedback optocoupler output should also  
be located close to the CONTROL and SOURCE pins of  
TOPSwitch-FX.  
1. Technical literature: Data Sheet, Application Notes, Design  
Ideas, etc.  
2. ransformer design spreadsheet.  
3. Engineering prototype boards.  
Y-Capacitor  
Up to date information on design tools can be found at Power  
Integrations Web site: www.power.com  
The Y-capacitor should be connected close to the secondary  
output return pin(s) and the primary DC input pin of the  
transformer (see Figures 29 and 30).  
Heat Sinking  
The tab of the Y package (TO-220) is internally electrically  
tied to the SOURCE pin. To avoid circulating currents, a heat  
sink attached to the tab should not be electrically tied to any  
nodes on the PC board.  
23  
Rev. C 06/15  
www.power.com  
TOP232-234  
ABSOLUTE MAXIMUM RATINGS(1,4)  
Lead Temperature(3) ...................................................260 °C  
Notes:  
1. All voltages referenced to SOURCE, TA = 25 °C.  
2. Normally limited by internal circuitry.  
DRAIN Pin Voltage ........................................... -0.3 to 700 V  
DRAIN Pin Peak Current: TOP232 ................................0.8 A  
TOP233 ................................1.6 A  
TOP234 ................................2.4 A  
CONTROL Pin Voltage......................................... -0.3 to 9 V  
CONTROL Pin Current..............................................100 mA  
MULTI-FUNCTION Pin Voltage............................. -0.3 to 9 V  
FREQUENCY Pin Voltage..................................... -0.3 to 9 V  
Operating Junction Temperature(2) .................. -40 to 150 °C  
3. 1/16” from case for 5 seconds.  
4. The Absolute Maximum Ratings specified may be applied,  
one at a time without causing permanent damage to the  
product. Exposure to Absolute Maximum Ratings for ex-  
tended periods of time may affect product reliability.  
THERMAL RESISTANCE  
Thermal Resistance: Y Package  
Notes:  
(θJA)(1) ...................................... 70 °C/W 1. Free standing with no heat sink.  
(θJC)(2) ........................................ 2 °C/W 2. Measured at the back surface of tab.  
P/G Package:  
3. Soldered to 0.36 sq. inch (232 mm2), 2oz. (610 gm/m2) copper clad.  
(θJA) .....................45 °C/W(3); 35 °C/W(4) 4. Soldered to 1 sq. inch (645 mm2), 2oz. (610 gm/m2) copper clad.  
(θJC)(5) ...................................... 11 °C/W 5. Measured on the SOURCE pin close to plastic interface.  
Conditions  
(Unless Otherwise Specified)  
Parameter  
Symbol  
Min  
Typ Max  
Units  
See Figure 34  
SOURCE = 0 V; TJ = -40 to 125 °C  
CONTROL FUNCTIONS  
FREQUENCY Pin  
Connected to SOURCE  
124  
132  
66  
140  
Switching  
IC = 4 mA;  
TJ = 25 °C  
kHz  
kHz  
fOSC  
Frequency  
FREQUENCY Pin  
Connected to CONTROL  
(average)  
61.5  
70.5  
4
2
132 kHz Operation  
66 kHz Operation  
Frequency Jitter  
Deviation  
f  
Frequency Jitter  
fM  
Hz  
%
250  
Modulation Rate  
IM ≤ IM(DC)  
75.0  
35.0  
78.0  
47.0  
82.0  
57.0  
Maximum Duty  
DCMAX  
IC = ICD1  
Cycle  
IM = 190 µA  
Minimum Duty  
DCMIN  
%
Cycle (Prior to  
0.8  
1.5  
2.7  
Cycle Skipping)  
TJ = 25 °C; DCMIN toDCMAX  
tSOFT  
ms  
Soft Start Time  
10  
14  
PWM  
Gain  
%/mA  
-27  
-22  
-17  
IC = 4 mA; TJ = 25 °C  
24  
Rev. C 06/15  
www.power.com  
TOP232-234  
Conditions  
(Unless Otherwise Specified)  
See Figure 34  
Parameter  
Symbol  
Min  
Typ Max  
Units  
SOURCE = 0 V; TJ = -40 to 125 °C  
CONTROL FUNCTIONS (cont.)  
PWM Gain  
- 0.01  
1.9  
%/mA/°C  
See Note A  
See Figure 4  
Temperature Drift  
External Bias  
Current  
lB  
mA  
1.2  
10  
2.8  
7.5  
22  
CONTROL  
Current at Start of  
Cycle Skipping  
TJ = 25 °C  
mA  
5.9  
Dynamic  
ZC  
IC = 4 mA; TJ = 25 °C  
15  
Impedance  
See Figure 32  
Dynamic  
0.18  
%/°C  
Impedance  
Temperature Drift  
Control Pin  
Internal Filter Pole  
kHz  
7
SHUTDOWN/AUTO-RESTART  
VC = 0 V  
VC = 5 V  
-5.0  
-3.0  
-3.8  
-1.9  
-2.6  
-0.8  
Control Pin  
Charging Current  
lC (CH)  
TJ = 25 °C  
mA  
Charging Current  
Temperature Drift  
See Note A  
0.5  
5.8  
%/°C  
V
Auto-restart Upper  
Threshold Voltage  
vC(AR)  
Auto-restart Lower  
Threshold Voltage  
4.5  
0.8  
2
4.8  
1.0  
4
5.1  
8
V
Auto-restart  
Hysteresis Voltage  
V
Auto-restart Duty  
Cycle  
%
Auto-restart  
Frequency  
1.0  
Hz  
2ꢀ  
Rev. C 06/15  
www.power.com  
TOP232-234  
Conditions  
(Unless Otherwise Specified)  
See Figure 34  
Parameter  
Symbol  
Min  
Typ Max  
Units  
SOURCE = 0 V; TJ = -40 to 125 °C  
MULTI-FUNCTION INPUT  
Line Undervoltage  
lUV  
µA  
TJ = 25 °C  
44  
50  
225  
10  
54  
Threshold Current  
µA  
µA  
Line Overvoltage or  
Threshold  
210  
240  
Remote ON/OFF  
Threshold Current  
and Hysteresis  
IOV  
TJ = 25 °C  
Hysteresis  
Remote ON/OFF  
Negative Threshold  
Current and  
Threshold  
µA  
µA  
-43  
-35  
-7  
-27  
IREM (N)  
TJ = 25 °C  
Hysteresis  
Hysteresis  
VM = VC  
300  
400  
520  
MULTI-FUNCTION  
Pin Short Circuit  
Current  
IM (SC)  
Normal Mode  
µA  
-300  
-240  
-180  
VM = 0 V  
Auto-restart Mode  
-110  
2.00  
2.50  
1.25  
-90  
-70  
lM = 50 µA  
lM = 225 µA  
lM = -50 µA  
lM = -150 µA  
2.60  
2.90  
1.32  
3.00  
3.30  
1.39  
MULTI-FUNCTION  
Pin Voltage  
V
VM  
1.18  
1.24  
1.30  
Maximum Duty  
Cycle Reduction  
Onset Threshold  
Current  
75  
90  
110  
µA  
%/µA  
mA  
IM (DC)  
TJ = 25 °C  
Maximum Duty  
Cycle Reduction  
Slope  
IM > IM (DC)  
0.30  
0.6  
MULTI-FUNCTION  
Pin Floating  
MULTI-FUNCTION  
1.1  
1.8  
Remote-OFF  
DRAIN Supply  
Current  
VDRAIN = 150 V  
Pin Shorted to  
CONTROL  
1.0  
From Remote On to Drain Turn-On  
See Note B  
µs  
µs  
1.5  
1.5  
2.5  
2.5  
4.0  
4.0  
Remote-ON Delay  
TRON  
Minimum Time Before Drain  
Turn-On to Disable Cycle  
See Note B  
Remote-OFF  
Setup Time  
TROFF  
26  
Rev. C 06/15  
www.power.com  
TOP232-234  
Conditions  
(Unless Otherwise Specified)  
See Figure 34  
Parameter  
Symbol  
Min Typ  
Max  
Units  
SOURCE = 0 V; TJ = -40 to 125 °C  
FREQUENCY INPUT  
FREQUENCY Pin  
Threshold Voltage  
VF  
IF  
See Note B  
VF = VC  
1.0  
10  
2.9  
22  
VC -1.0  
40  
V
FREQUENCY Pin  
Input Current  
µA  
CIRCUIT PROTECTION  
TOP232  
TJ= 25 °C  
Internal; di/dt = 100mA/µs  
0.465 0.500 0.535  
0.930 1.000 1.070  
1.395 1.500 1.605  
See Note C  
Internal; di/dt = 200mA/µs  
TOP233  
TJ= 25 °C  
Self Protection  
Current Limit  
ILIMIT  
A
A
See Note C  
Internal; di/dt = 300mA/µs  
TOP234  
TJ= 25 °C  
See Note C  
0.75 x  
ILIMIT(MIN)  
≤ 85 VAC  
(Rectified Line Input)  
See Figure 33  
TJ = 25 °C  
IINIT  
Initial Current Limit  
0.6 x  
ILIMIT(MIN)  
265 VAC  
(Rectified Line Input)  
Leading Edge  
Blanking Time  
tLEB  
tILD  
ns  
ns  
IC = 4 mA  
200  
100  
Current Limit Delay  
IC = 4 mA  
Thermal Shutdown  
Temperature  
125  
2.0  
135  
150  
4.3  
°C  
°C  
V
Thermal Shutdown  
Hysteresis  
70  
Power-up Reset  
Threshold Voltage  
3.3  
VC(RESET)  
Figure 34, S1 open  
OUTPUT  
TJ = 25 °C  
TJ = 100 °C  
TJ = 25 °C  
TJ = 100 °C  
TJ = 25 °C  
TJ = 100 °C  
TOP232  
ID = 50 mA  
15.6  
25.7  
7.8  
18.0  
30.0  
9.0  
ON-State  
Resistance  
TOP233  
ID = 100 mA  
RDS(ON)  
12.9  
5.2  
15.0  
6.0  
TOP234  
ID = 150 mA  
8.6  
10.0  
27  
Rev. C 06/15  
www.power.com  
TOP232-234  
Conditions  
(Unless Otherwise Specified)  
See Figure 34  
Parameter  
Symbol  
Min  
Typ  
Max  
Units  
SOURCE = 0 V; TJ = -40 to 125 °C  
OUTPUT (cont.)  
VM = Floating; IC = 4mA  
VDS = 560 V; TJ = 125 °C  
Off-State  
Current  
IDSS  
150  
µA  
V
VM = Floating; IC = 4mA  
ID = 100 µA; TJ = 25 °C  
Breakdown  
Voltage  
700  
BVDSS  
tR  
100  
50  
ns  
Rise Time  
Fall Time  
Measured in a Typical  
Flyback Converter Application  
tF  
ns  
SUPPLY VOLTAGE CHARACTERISTICS  
DRAIN Supply  
Voltage  
36  
V
See Note D  
Shunt Regulator  
Voltage  
VC(SHUNT)  
5.60  
5.85  
50  
6.10  
V
IC = 4 mA  
Shunt Regulator  
Temperature Drift  
ppm/°C  
Output  
MOSFET Enabled  
VM = 0 V  
lCD1  
1.0  
0.3  
1.5  
0.6  
2.0  
1.0  
Control Supply/  
Discharge Current  
mA  
Output  
MOSFET Disabled  
VM = 0 V  
lCD2  
NOTES:  
A. For specifications with negative values, a negative temperature coefficient corresponds to an increase in magnitude  
with increasing temperature, and a positive temperature coefficient corresponds to a decrease in magnitude with  
increasing temperature.  
B. Guaranteed by characterization. Not tested in production.  
C. For externally adjusted current limit values, please refer to the graph (Current Limit vs. External Current Limit Resis-  
tance) in the Typical Performance Characteristics section.  
D. It is possible to start up and operate TOPSwitch-FX at DRAIN voltages well below 36 V. However, the CONTROL pin  
charging current is reduced, which affects start-up time, auto-restart frequency, and auto-restart duty cycle. Refer to  
the characteristic graph on CONTROL pin charge current (IC) vs. DRAIN voltage for low voltage operation characteristics.  
28  
Rev. C 06/15  
www.power.com  
TOP232-234  
t
2
t
1
HV  
90%  
90%  
t
t
DRAIN  
VOLTAGE  
1
2
D =  
10%  
0 V  
PI-2039-033001  
Figure 31. Duty Cycle Measurement.  
t
(Blanking Time)  
LEB  
1.3  
1.2  
1.1  
1.0  
0.9  
0.8  
0.7  
0.6  
0.5  
0.4  
0.3  
0.2  
0.1  
120  
100  
80  
60  
40  
20  
0
IINIT(MIN) @ 85 VAC  
IINIT(MIN) @ 265 VAC  
ILIMIT(MAX) @ 25 ˚C  
1
Dynamic  
ILIMIT(MIN) @ 25 ˚C  
=
Impedance Slope  
0
0
1
2
3
4
5
6
7
8
0
2
4
6
8
10  
CONTROL Pin Voltage (V)  
Time (µs)  
Figure 33. Drain Current Operating Envelope.  
Figure 32. CONTROL Pin I-V Characteristic.  
S1  
470  
5 W  
100 kΩ  
S3  
5-50 V  
40 V  
0-60 kΩ  
M
D
S
CONTROL  
470 Ω  
C
TOPSwitch-FX  
S2  
F
S4  
0-15 V  
47 µF  
0.1 µF  
NOTES: 1. This test circuit is not applicable for current limit or output characteristic measurements.  
2. For P and G packages, short all SOURCE pins together.  
PI-2538-062615  
Figure 34. TOPSwitch-FX General Test Circuit.  
29  
Rev. C 06/15  
www.power.com  
TOP232-234  
BENCH TEST PRECAUTIONS FOR EVALUATION OF ELECTRICAL CHARACTERISTICS  
while in this auto-restart mode, there is only a 12.5% chance  
that the CONTROL pin oscillation will be in the correct state  
(drain active state) so that the continuous drain voltage  
waveform may be observed. It is recommended that the VC  
power supply be turned on first and the DRAIN pin power  
supply second if continuous drain voltage waveforms are to be  
observed. The 12.5% chance of being in the correct state is  
due to the divide-by-8 counter. Temporarily shorting the  
CONTROL pin to the SOURCE pin will reset TOPSwitch-FX,  
which then will come up in the correct state.  
The following precautions should be followed when testing  
TOPSwitch-FX by itself outside of a power supply. The  
schematic shown in Figure 34 is suggested for laboratory  
testing of TOPSwitch-FX.  
When the DRAIN pin supply is turned on, the part will be in the  
auto-restart mode. The CONTROL pin voltage will be  
oscillating at a low frequency between 4.8 and 5.8 V and the  
drain is turned on every eighth cycle of the CONTROL pin  
oscillation. If the CONTROL pin power supply is turned on  
Typical Performance Characteristics  
CURRENT LIMIT vs. MULTI-FUNCTION  
PIN CURRENT  
PI-2540-033001  
200  
180  
160  
140  
120  
100  
1.0  
.9  
.8  
.7  
.6  
Scaling Factors:  
.5  
.4  
TOP234 1.50  
TOP233 1.00  
TOP232 0.50  
80  
60  
.3  
-250  
-200  
-150  
-100  
-50  
0
IM (µA)  
CURRENT LIMIT vs. EXTERNAL  
CURRENT LIMIT RESISTANCE  
PI-2539-033001  
1.1  
1.0  
200  
Scaling Factors:  
TOP234 1.50  
TOP233 1.00  
TOP232 0.50  
.9  
.8  
.7  
.6  
180  
160  
140  
120  
Maximum  
Minimum  
Typical  
.5  
.4  
.3  
100  
80  
Maximum and minimum levels  
are based on characterization.  
60  
30K  
0
5K  
10K  
15K  
20K  
25K  
External Current Limit Resistor RIL ()  
30  
Rev. C 06/15  
www.power.com  
TOP232-234  
Typical Performance Characteristics (cont.)  
BREAKDOWN vs. TEMPERATURE  
FREQUENCY vs. TEMPERATURE  
1.2  
1.1  
1.0  
0.8  
0.6  
0.4  
1.0  
0.9  
0.2  
0
-50 -25  
0
25 50 75 100 125 150  
-50 -25  
0
25 50 75 100 125 150  
Junction Temperature (°C)  
Junction Temperature (°C)  
OVER-VOLTAGE THRESHOLD  
vs. TEMPERATURE  
UNDER-VOLTAGE THRESHOLD  
vs. TEMPERATURE  
Junction Temperature (°C)  
Junction Temperature (°C)  
OVER-VOLTAGE THRESHOLD  
vs. TEMPERATURE  
UNDER-VOLTAGE THRESHOLD  
vs. TEMPERATURE  
Junction Temperature (°C)  
Junction Temperature (°C)  
31  
Rev. C 06/15  
www.power.com  
TOP232-234  
Typical Performance Characteristics (cont.)  
MULTI-FUNCTION PIN VOLTAGE  
vs. CURRENT  
MULTI-FUNCTION PIN VOLTAGE  
vs. CURRENT (EXPANDED)  
1.6  
1.4  
1.2  
1.0  
0.8  
0.6  
0.4  
0.2  
6
5
4
3
2
See  
Expanded  
Version  
1
0
0
-300 -250 -200 -150 -100 -50  
0
-300 -200 -100  
0
100 200 300 400 500  
MULTI-FUNCTION Pin Current (mA)  
MULTI-FUNCTION Pin Current (µA)  
CONTROL CURRENT at START of  
CYCLE SKIPPING vs. TEMPERATURE  
MAX. DUTY CYCLE REDUCTION ONSET  
THRESHOLD CURRENT vs. TEMPERATURE  
Junction Temperature (°C)  
Junction Temperature (°C)  
I vs. DRAIN VOLTAGE  
OUTPUT CHARACTERISTICS  
C
1.5  
2
VC = 5 V  
TCASE = 25 °C  
T
CASE = 100 °C  
1.6  
1.2  
1
0.5  
0
Scaling Factors:  
0.8  
0.4  
0
TOP234 1.00  
TOP233 0.67  
TOP232 0.33  
0
20  
40  
60  
80  
100  
0
2
4
6
8
10  
DRAIN Voltage (V)  
DRAIN Voltage (V)  
32  
Rev. C 06/15  
www.power.com  
TOP232-234  
Typical Performance Characteristics (cont.)  
C
OSS  
vs. DRAIN VOLTAGE  
DRAIN CAPACITANCE POWER (132 kHz)  
1000  
Scaling Factors:  
Scaling Factors:  
300  
TOP234 1.00  
TOP233 0.67  
TOP232 0.33  
TOP234 1.00  
TOP233 0.67  
TOP232 0.33  
200  
100  
100  
10  
0
0
200  
400  
600  
0
200  
400  
600  
DRAIN Voltage (V)  
DRAIN Voltage (V)  
33  
Rev. C 06/15  
www.power.com  
TOP232-234  
TO-220-7B  
.165 (4.19)  
.185 (4.70)  
.400 (10.16)  
.415 (10.54)  
.045 (1.14)  
.055 (1.40)  
.146 (3.71)  
.156 (3.96)  
.108 (2.74) REF  
.236 (5.99)  
.260 (6.60)  
.570 (14.48)  
REF.  
.467 (11.86)  
.487 (12.37)  
7° TYP.  
.670 (17.02)  
REF.  
.860 (21.84)  
.880 (22.35)  
.095 (2.41)  
.115 (2.92)  
.028 (.71)  
.032 (.81)  
.040 (1.02)  
.060 (1.52)  
.010 (.25) M  
.015 (.38)  
.020 (.51)  
.040 (1.02)  
.060 (1.52)  
.050 (1.27) BSC  
.150 (3.81) BSC  
.190 (4.83)  
.210 (5.33)  
Notes:  
.050 (1.27)  
1. Controlling dimensions are inches. Millimeter  
dimensions are shown in parentheses.  
2. Pin locations start with Pin 1, and continue  
from left to right when viewed from the front.  
Pins 2 and 6 are omitted.  
3. Dimensions do not include mold flash or  
other protrusions. Mold flash or protrusions  
shall not exceed .006 (.15mm) on any side.  
4. Minimum metal to metal spacing at the pack-  
age body for omitted pin locations is .068  
inch (1.73 mm).  
.050 (1.27)  
.050 (1.27)  
.200 (5.08)  
.050 (1.27)  
.180 (4.58)  
5. Position of the formed leads to be measured  
at the mounting plane, .670 inch (17.02 mm)  
below the hole center.  
.150 (3.81)  
.150 (3.81)  
MOUNTING HOLE PATTERN  
Y07B  
6. All terminals are solder plated.  
34  
Rev. C 06/15  
www.power.com  
TOP232-234  
PDIP-8B (P Package)  
D S .004 (.10)  
Notes:  
.137 (3.48)  
MINIMUM  
1. Package dimensions conform to JEDEC specification  
MS-001-AB (Issue B 7/85) for standard dual-in-line (DIP)  
package with .300 inch row spacing.  
-E-  
2. Controlling dimensions are inches. Millimeter sizes are  
shown in parentheses.  
3. Dimensions shown do not include mold flash or other  
protrusions. Mold flash or protrusions shall not exceed  
.006 (.15) on any side.  
.240 (6.10)  
.260 (6.60)  
4. Pin locations start with Pin 1, and continue counter-clock-  
wise to Pin 8 when viewed from the top. The notch and/or  
dimple are aids in locating Pin 1. Pin 6 is omitted.  
5. Minimum metal to metal spacing at the package body for  
the omitted lead location is .137 inch (3.48 mm).  
6. Lead width measured at package body.  
Pin 1  
-D-  
7. Lead spacing measured with the leads constrained to be  
perpendicular to plane T.  
.367 (9.32)  
.387 (9.83)  
.057 (1.45)  
.068 (1.73)  
(NOTE 6)  
.125 (3.18)  
.145 (3.68)  
.015 (.38)  
MINIMUM  
-T-  
SEATING  
PLANE  
.008 (.20)  
.015 (.38)  
.120 (3.05)  
.140 (3.56)  
.300 (7.62) BSC  
(NOTE 7)  
.100 (2.54) BSC  
.048 (1.22)  
.053 (1.35)  
P08B  
.300 (7.62)  
.390 (9.91)  
.014 (.36)  
.022 (.56)  
T E D S .010 (.25) M  
PI-2551-040110  
SMD-8B (G Package)  
D S .004 (.10)  
Notes:  
.137 (3.48)  
MINIMUM  
1. Controlling dimensions are  
inches. Millimeter sizes are  
shown in parentheses.  
-E-  
2. Dimensions shown do not  
include mold flash or other  
protrusions. Mold flash or  
protrusions shall not exceed  
.006 (.15) on any side.  
3. Pin locations start with Pin 1,  
and continue counter-clock-  
wise to Pin 8 when viewed  
from the top. Pin 6 is omitted.  
4. Minimum metal to metal  
spacing at the package body  
for the omitted lead location  
is .137 inch (3.48 mm).  
.372 (9.45)  
.388 (9.86)  
.240 (6.10)  
.260 (6.60)  
.420  
.010 (.25)  
E S  
.046 .060 .060 .046  
.080  
Pin 1  
Pin 1  
-D-  
5. Lead width measured at  
package body.  
6. D and E are referenced  
datums on the package  
body.  
.086  
.186  
.100 (2.54) (BSC)  
.286  
.367 (9.32)  
.387 (9.83)  
Solder Pad Dimensions  
.057 (1.45)  
.068 (1.73)  
(NOTE 5)  
.125 (3.18)  
.145 (3.68)  
.004 (.10)  
.032 (.81)  
.037 (.94)  
.048 (1.22)  
.053 (1.35)  
°
°
.009 (.23)  
0 - 8  
.036 (0.91)  
.044 (1.12)  
.004 (.10)  
.012 (.30)  
G08B  
PI-2546-040110  
35  
Rev. C 06/15  
www.power.com  
TOP232-234  
Revision  
Notes  
Date  
A
Initial Release.  
01/00  
Corrected rounding of operating frequency (132/66 kHz), corrected spelling and corrected Storage Temperature θJC and  
updated nomenclature in parameter table.  
B
C
07/01  
06/15  
Updated with new Brand Style Logo.  
For the latest updates, visit our website: www.power.com  
Power Integrations reserves the right to make changes to its products at any time to improve reliability or manufacturability. Power  
Integrations does not assume any liability arising from the use of any device or circuit described herein. POWER INTEGRATIONS MAKES  
NO WARRANTY HEREIN AND SPECIFICALLY DISCLAIMS ALL WARRANTIES INCLUDING, WITHOUT LIMITATION, THE IMPLIED  
WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, AND NON-INFRINGEMENT OF THIRD PARTY RIGHTS.  
Patent Information  
The products and applications illustrated herein (including transformer construction and circuits external to the products) may be covered  
by one or more U.S. and foreign patents, or potentially by pending U.S. and foreign patent applications assigned to Power Integrations.  
A complete list of Power Integrations patents may be found at www.power.com. Power Integrations grants its customers a license under  
certain patent rights as set forth at http://www.power.com/ip.htm.  
Life Support Policy  
POWER INTEGRATIONS PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR  
SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT OF POWER INTEGRATIONS. As used herein:  
1. A Life support device or system is one which, (i) is intended for surgical implant into the body, or (ii) supports or sustains life, and (iii)  
whose failure to perform, when properly used in accordance with instructions for use, can be reasonably expected to result in significant  
injury or death to the user.  
2. A critical component is any component of a life support device or system whose failure to perform can be reasonably expected to cause  
the failure of the life support device or system, or to affect its safety or effectiveness.  
The PI logo, TOPSwitch, TinySwitch, LinkSwitch, LYTSwitch, InnoSwitch, DPA-Switch, PeakSwitch, CAPZero, SENZero, LinkZero,  
HiperPFS, HiperTFS, HiperLCS, Qspeed, EcoSmart, Clampless, E-Shield, Filterfuse, FluxLink, StakFET, PI Expert and PI FACTS are  
trademarks of Power Integrations, Inc. Other trademarks are property of their respective companies. ©2014, Power Integrations, Inc.  
Power Integrations Worldwide Sales Support Locations  
World Headquarters  
Germany  
Japan  
Taiwan  
5245 Hellyer Avenue  
Lindwurmstrasse 114  
80337 Munich  
Germany  
Phone: +49-895-527-39110  
Fax: +49-895-527-39200  
e-mail: eurosales@power.com  
Kosei Dai-3 Bldg.  
2-12-11, Shin-Yokohama,  
Kohoku-ku  
Yokohama-shi Kanagwan  
222-0033 Japan  
Phone: +81-45-471-1021  
Fax: +81-45-471-3717  
e-mail: japansales@power.com  
5F, No. 318, Nei Hu Rd., Sec. 1  
Nei Hu Dist.  
Taipei 11493, Taiwan R.O.C.  
Phone: +886-2-2659-4570  
Fax: +886-2-2659-4550  
e-mail: taiwansales@power.com  
San Jose, CA 95138, USA.  
Main: +1-408-414-9200  
Customer Service:  
Phone: +1-408-414-9665  
Fax: +1-408-414-9765  
e-mail: usasales@power.com  
India  
UK  
China (Shanghai)  
Rm 1601/1610, Tower 1,  
Kerry Everbright City  
No. 218 Tianmu Road West,  
Shanghai, P.R.C. 200070  
Phone: +86-21-6354-6323  
Fax: +86-21-6354-6325  
e-mail: chinasales@power.com  
#1, 14th Main Road  
Vasanthanagar  
Bangalore-560052 India  
Phone: +91-80-4113-8020  
Fax: +91-80-4113-8023  
e-mail: indiasales@power.com  
First Floor, Unit 15, Meadway  
Court, Rutherford Close,  
Stevenage, Herts. SG1 2EF  
United Kingdom  
Phone: +44 (0) 1252-730-141  
Fax: +44 (0) 1252-727-689  
e-mail: eurosales@power.com  
Korea  
RM 602, 6FL  
Korea City Air Terminal B/D, 159-6  
Samsung-Dong, Kangnam-Gu,  
Seoul, 135-728, Korea  
Phone: +82-2-2016-6610  
Fax: +82-2-2016-6630  
e-mail: koreasales@power.com  
Italy  
Via Milanese 20, 3rd. Fl.  
20099 Sesto San Giovanni (MI)  
Italy  
Phone: +39-024-550-8701  
Fax: +39-028-928-6009  
e-mail: eurosales@power.com  
China (Shenzhen)  
17/F, Hivac Building, No. 2,  
Keji Nan 8th Road, Nanshan  
District, Shenzhen, China,  
518057  
Singapore  
51 Newton Road  
#19-01/05 Goldhill Plaza  
Singapore, 308900  
Phone: +86-755-8672-8689  
Fax: +86-755-8672-8690  
e-mail: chinasales@power.com  
Phone: +65-6358-2160  
Fax: +65-6358-2015  
e-mail: singaporesales@power.com  
36  
Rev. C 06/15  
www.power.com  

相关型号:

TOP242

Family Extended Power, Design Flexible,Integrated Off-line Switcher
POWERINT

TOP242-249

Family Extended Power, Design Flexible,Integrated Off-line Switcher
POWERINT

TOP242-250

TOPSwitch-GX Family Extended Power, Design Flexible, EcoSmart, Integrated Off-line Switcher
POWERINT

TOP242F

TOPSwitch -GX Family Extended Power, Design Flexible, EcoSmart, Integrated Off-line Switcher
POWERINT

TOP242F-

TOPSwitch-GX Family Extended Power, Design Flexible, EcoSmart, Integrated Off-line Switcher
POWERINT

TOP242F-TL

TOPSwitch-GX Family Extended Power, Design Flexible, EcoSmart, Integrated Off-line Switcher
POWERINT

TOP242FN

IC OFFLINE SWIT UVLO HV TO262
POWERINT

TOP242FN-

TOPSwitch-GX Family Extended Power, Design Flexible, EcoSmart, Integrated Off-line Switcher
POWERINT

TOP242FN-TL

TOPSwitch-GX Family Extended Power, Design Flexible, EcoSmart, Integrated Off-line Switcher
POWERINT

TOP242G

Family Extended Power, Design Flexible,Integrated Off-line Switcher
POWERINT

TOP242G-

TOPSwitch-GX Family Extended Power, Design Flexible, EcoSmart, Integrated Off-line Switcher
POWERINT

TOP242G-TL

TOPSwitch-GX Family Extended Power, Design Flexible, EcoSmart, Integrated Off-line Switcher
POWERINT