AN-9745 [FAIRCHILD]
Design Guide for TRIAC Dimmable LED Driver Using FL7730; 设计指南TRIAC可调光LED驱动器采用FL7730
| 型号： | AN-9745 |
| 厂家： | 
FAIRCHILD SEMICONDUCTOR |
| 描述： | Design Guide for TRIAC Dimmable LED Driver Using FL7730 |
| 文件： | 总11页 (文件大小：1454K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
www.fairchildsemi.com
AN-9745
Design Guide for TRIAC Dimmable LED Driver Using FL7730
Introduction
An LED has become a promising light source for replacing
conventional lighting systems, such as fluorescent and
incandescent lights. Especially in the conventional TRIAC
dimmer infrastructure, there has been much research into
development of an LED bulb compatible with TRIAC
dimmers. Because the incandescent light source consumes a
hundred watt with short life time, an LED bulb can be the
excellent substitute with considerably less power dissipation
and longer life.
Figure 1. TRIAC Dimmer and LED Bulb
The biggest recent issue of TRIAC dimmable LED bulb is
dimmer compatibility. The conventional TRIAC dimmer
was originally designed to handle hundreds of watts
induced by incandescent bulbs. An LED bulb consuming
less than 20 W should interact with those dimmers
composed of high-power devices. If the interaction between
dimmer and LED bulb is not stabilized, visible flicker is
perceptible.
To manage the interaction without flicker, some
requirements for dimmer operation need to be considered.
TRIAC dimmer needs latching current at firing and holding
current during TRIAC turn-on after firing. If those two
currents are not met, TRIAC dimmer misfires and LED
light flickers. Figure 1 shows the connection of TRIAC
dimmer and LED bulb. As shown in Figure 2, the TRIAC
dimmer blocks input line in the beginning of line cycle, then
connects input line and LED bulb after firing. The TRIAC
dimmer turns off if latching or holding current flowing
through the dimmer is inadequate, as shown in Figure 3.
Figure 2. Dimmer Operation with Adequate
Latching / Holding Current
The latching and holding currents are different from dimmer
models. The typical range of latching and holding currents
is around 5 ~ 50 mA. Those operating requirement do not
cause problems using incandescent bulbs due to high power
consumption. An LED bulb with less than 20 W output
power cannot maintain this amount of current over the
whole line cycle.
This application note provides a practical guideline of
TRIAC dimmable LED bulb board design. Passive and
active bleeder design guides detail how to maintain latching
and holding current without visible flicker. Active damper
design improves efficiency by minimizing the count of
external components. The input filter design section covers
the effect of filter components on PF, THD, and EMI.
Figure 3. Dimmer Operation with Inadequate
Latching / Holding Current
© 2011 Fairchild Semiconductor Corporation
Rev. 1.0.2 • 10/11/12
www.fairchildsemi.com
AN-9745
APPLICATION NOTE
1. Passive Bleeder Design
The passive bleeder is designed to supply latching and
holding current to eliminate misfire and flicker. Figure 4
shows a board schematic using a passive bleeder.
Figure 5. Line Current, Small Bleeder Capacitor (CB)
Figure 4. LED Driver Schematic with Passive Bleeder
A passive bleeder is composed of a resistor (RB) and a
capacitor (CB). LF1 and LF2 are input filter inductors. CIN is
input filter capacitor and RD is damper resistor.
In dimmable board design, a resistor (ex. RB, RD) needs to
be connected in series with a capacitor (ex. CB, CIN) in case
that the capacitor is located in between input lines. Without
the series resistor, a large voltage and current spike occurs
due to the quickly charged energy in the capacitor at
dimmer firing. The current spike can damage the TRIAC
dimmer, especially when LED bulbs are connected in
parallel with the dimmer because the sum of the current
spike from each LED bulb can be over the rated current of
the TRIAC dimmer. Current ringing after the current spike
can also cause the TRIAC dimmer to misfire due to
negative current of less than the holding current in the
oscillation. The voltage spike can destroy external
components if it is over the rated breakdown voltage.
Figure 6. Line Current, Large Bleeder Capacitor (CB)
ILINE should be higher than latching and holding current
because ILINE directly flows through the TRIAC dimmer. In
Figure 5, ILINE at firing is not large enough due to the small
CB. The TRIAC dimmer can misfire right after firing, as
shown in Figure 3. In Figure 6, ILINE is higher at dimmer
firing with the large CB, which can maintain normal turn-on
state of TRIAC, as shown in Figure 2. Therefore, a large CB
maintains dimmer firing better than a small CB by supplying
higher IB.
However, a large CB has a drawback in PF, THD, and
efficiency. Table
1 shows the system performance
The passive bleeder includes a hundreds-of-nF capacitor
(CB) to provide latching and holding current. To remove the
voltage and current spike described above, a bleeder resistor
(RB) is necessary to dampen the spike.
comparison between 100 nF and 220 nF CB. CB has a
significant influence on PF and power dissipation in RB.
Compared to 100 nF CB, the 220 nF CB seriously drops PF
and increases power dissipation of RB due to the larger
charging and discharging current of CB.
1.1 Passive Bleeder Capacitor (CB) Selection
Table 1. CB Effect on System Performance
The capacity of CB determines the bleeder current to retain
TRIAC turn-on. In terms of TRIAC dimming, bigger CB has
better stability in dimming control due to large bleeder
current. Figure 5 and Figure 6 show the line current of small
and large bleeder capacitors. The input current (IIN) is the
current from the flyback converter behind the bridge diode.
IIN is in-phase with line voltage by power factor correction
controlled by FL7730. IB is bleeder current and line current
(ILINE) is the sum of IIN and IB.
TEST CONDITION: VIN = 230 VAC, POUT = 8 W, RB = 2 kΩ
PF
THD
13%
11%
PD in RB
162 mW
684 mW
CB [100 nF]
CB [220 nF]
0.93
0.85
Therefore, TRIAC dimming control and PF require
balanced trade-off when selecting CB in the passive bleeder.
Especially in high-line bulb with high PF requirements;
these two factors can make finding the proper CB
a
challenge. In the CB selection, the first step is to see IB
during dimmer firing by changing CB to check if there is
any misfire at dimmer firing due to inadequate IB. In the
range of CB without abnormal operation in dimmer firing,
choose the minimum CB for higher PF and efficiency. The
EMI is not affected by CB because RB is connected in series
and interrupts noise filtering by CB.
© 2011 Fairchild Semiconductor Corporation
Rev. 1.0.2 • 10/11/12
www.fairchildsemi.com
2
AN-9745
APPLICATION NOTE
1.2 Passive Bleeder Resistor (RB) Selection
2. Active Bleeder Design
RB is the damper for reducing the spike current caused by
quick charging of CB at firing. Figure 7 shows line current
with excessively large RB. Too large RB dampens IB too
much and limits IB less than latching current at firing. Then,
the TRIAC dimmer can misfire right after firing so that
visible flicker is appears.
Another method to maintain TRIAC holding current is
active bleeding technique. The active bleeder can cover a
wider range of TRIAC turn-on in a line input cycle
compared to passive bleeder. The proposed active bleeder
retains TRIAC holding current by regulating input current,
which minimizes power loss in the bleeder circuit.
Figure 7. Line Current with Excessively Large RB
Figure 8 shows ILINE with excessively small RB. If RB is too
small, RB doesn’t fully dampen the spike current and
ringing current occurs. The ringing current fluctuates under
the negative IB, which causes misfire of the TRIAC dimmer
and visible flicker.
Figure 9. Active Bleeder Schematic
In Figure 9, ILINE is the sum of IB (active bleeder current)
and IIN (flyback input current). RSENSE is sensing resistor
detecting line current, ILINE. CFILTER is the filter capacitor to
filter switching noise at RSENSE voltage. QREG is a shunt
regulator, such as KA431. At dimmer firing, a large current
spike causes a large voltage drop at RSENSE. ZDLIM limits
RSENSE voltage to protect reference block of QREG. Biasing
current to drive QBLEED (bleeder MOSFET) as a linear
regulator is supplied by auxiliary winding. The biasing
circuit consists of DBIAS and CBIAS. The gate of QBLEED is
controlled by the CBIAS biasing voltage and cathode of QREG
.
The amount of driving current is limited by RSOURCE and
RSINK. CCOMP reduces response of the regulation loop. RCOMP
compensates control loop as a negative feedback resistor.
Figure 8. Line Current with Excessively Small RB
IB
Another consideration in RB selection is power loss. Table 2
compares system performance using two different bleeder
resistors. In the system specification, RB doesn’t affect PF
and THD; however, large RB makes increases power
dissipation in RB.
ILINE regulation
Set holding current
ILINE
= VREF(QREG) / RSENSE
(IIN+IB)
Table 2. RB Effect on System Performance
TEST CONDITION: Vin = 230 VAC, POUT = 8 W, CB = 100 nF
IIN
PF
THD
13%
13%
PD IN RB
100 mW
162 mW
RB [1 kΩ]
RB [2 kΩ]
0.93
0.93
Figure 10.Line Current Using Active Bleeder
In RB selection, the excessively large and small RB values
should be found first. Then, the minimum RB can be
selected in the proper range of RB for better efficiency.
© 2011 Fairchild Semiconductor Corporation
Rev. 1.0.2 • 10/11/12
www.fairchildsemi.com
3
AN-9745
APPLICATION NOTE
The functional operation is shown in Figure 10. In this
active bleeder, VGS (gate-source voltage) of QBLEED is
increased and IB becomes higher when RSENSE voltage is less
than VREF of QREG. The holding current is given as:
VREF (QREG
)
IHOLD
(1)
RSENSE
In the selection of the IHOLD, there is a trade-off between
dimmer compatibility and system efficiency. If IHOLD is set
high, the active bleeder is more compatible with more
dimmers; but the amount of IB increases with more power
dissipation in the active bleeder.
Figure 12.Measured Waveform at High Dimming Angle
RSOURCE, RSINK, CCOMP, RCOMP, and CFILTER have a close
relationship with the feedback response of the active
bleeder. Smaller resistance (RSOURCE, RSINK, RCOMP) and
capacitance (CCOMP, CFILTER) increase the speed of the
feedback loop. If feedback loop is too fast, IB oscillates with
a large current ripple.
The operation of the active bleeder should be synchronized
with the normal IC operation period. When the IC is in an
abnormal condition, such as an LED short and open, there is
no IIN due to shutdown gate signal. If active bleeder is still
activated in this abnormal condition, the active bleeder
should maintain holding current without IIN and the power
dissipation in the active bleeder is very high and QBLEED is
thermally destroyed. Therefore, the biasing current should
come from the auxiliary winding. Then, the active bleeder
can be disabled when switching is shut down.
Figure 13.Measured Waveform at Low Dimming Angle
Figure 12 and Figure 13 show the waveforms of the active
bleeder at high and low dimming angle. At low dimming
angle, output current is reduced by the dimming function in
FL7730. The active bleeder should compensate more IB
current due to the reduced IIN (C3). That is why the power
dissipation in the active bleeder is in the middle dimming
angle range. To check the maximum bleeder temperature,
the test condition should be a middle dimming angle and
maximum line input voltage.
Figure 11 is a design example of an active bleeder. Probe
ground is connected to VREF of the shunt regulator
(KA431). C1 is the RSENSE voltage and C2 is the input
voltage. C3 is the bleeder MOSFET source voltage, which
is proportional to bleeder current. C4 is current probed line
current.
C4(ILINE
)
C2(VIN)
3. Active Damper Design
1N4003
3k
Aux.
winding
A resistive damper is necessary in series with input filter
capacitor (CIN) when TRIAC dimmer is fired. At dimmer
firing, a large current spike is induced through input line to
quickly charge CIN. Without the resistive damper, the large
spike creates line current oscillation, causing dimmer
misfire and damage to the TRIAC dimmer with the
excessive current. While the damper resistor suppresses the
spike current, the power loss in the damper resistor is very
high. The damper resistor not only dampens the spike
current, but also handles the input current from the flyback.
FQPF2N50
1k
C3(QBLEED SOURCE)
100/0.5W
680n
100n
KA431
100/0.5W
100n
C1(V_RSENSE
)
Probe GND
Therefore, Fairchild’s proprietary active damper is proposed
to reduce the power loss with minimized external
components. In Figure 14, RAD is the active damper resistor
3V
and QAD is damper MOSFET to reduce power loss of RAD
.
Figure 11.Example of Active Bleeder in 8 W Bulb
RD and CD are delay circuit components and DD is reset
diode to discharge CD.
© 2011 Fairchild Semiconductor Corporation
Rev. 1.0.2 • 10/11/12
www.fairchildsemi.com
4
AN-9745
APPLICATION NOTE
RD
CD
current. Therefore, the active damper is strongly
recommended at low line model.
VGATE
DD
Table 3. Passive vs. Active Damper Power Loss
Damper Power
QAD
VAD
IIN
Dissipation [mW]
POUT = 8W
RAD
VIN: 110 VAC VIN: 220 VAC
Single-Stage
Flyback
PASSIVE DAMPER, 200 ꢀ
1200
278
290
161
CIN
VIN
ACTIVE DAMPER, 200 ꢀ +
FQN1N50C (VTH: 2~4 V)
ACTIVE DAMPER, 200 ꢀ +
FDD10N20LZ (VTH: 1~2.5 V)
171
113
Figure 14.Active Damper Schematic
3.1 Active Damper Resistor (RAD) Selection
A voltage and current spike should be checked first when
selecting RAD. Voltage spikes can damage the MOSFET and
filter capacitor over the rated voltage. Current spikes create
current ringing at dimmer firing. As shown in Figure 16, IIN
ringing occurs at firing with small RAD. This ringing current
drops IIN and the lowered IIN can lead to misfire of the
dimmer and visible flicker. Also, a large peak current spike
by using small RAD might damage the TRIAC dimmer,
especially when the dimming LED bulbs are connected in
parallel. Therefore, check points when selecting RAD are:
.
Voltage spike (should be less than the part’s breakdown
voltage.)
.
Current spike (should be less than the TRIAC dimmer’s
rated current. If considering connecting bulbs in
parallel, the current spike should be lower inversely
proportional to the number of LED bulbs.)
.
Current ringing (check the dropped IIN at firing if it is
enough higher than TRIAC holding current.)
After checking the above considerations, choose the
minimum RAD to maximize efficiency.
Figure 15.Active Damper Waveforms
Figure 15 shows the operational waveforms of the active
damper. Mode analysis is as according to the sequence:
M1: Dimmer turn-off period; QAD turns off.
M2: Dimmer is fired and spike current occurs.
VGATE is gradually increased by the delay circuit (RD
and CD)
M3: QAD turns on by the charged VGATE
VAD is regulated as VTH of QAD
.
.
M4: CD is discharged by DD and VGATE is reset for the
next line cycle. The discharging current path is
DD - RAD - CD.
During M3 period, QAD can considerably reduce power loss
in RAD by regulating VAD as its threshold voltage (VTH).
Table 3 shows power dissipation of passive and active
dampers. The power loss of active damper is much lower
than passive damper resistor. At low line (110 VAC), input
current is high and the damper resistor handles the large
Figure 16.VIN and IIN with Small Damper Resistor (RAD
)
3.2 Active Damper MOSFET (QAD) Selection
The maximum VAD should be less than the breakdown
voltage of QAD. After selecting RAD, maximum VAD can be
checked at 90º dimming angle and the highest input line
© 2011 Fairchild Semiconductor Corporation
Rev. 1.0.2 • 10/11/12
www.fairchildsemi.com
5
AN-9745
APPLICATION NOTE
voltage. Then, choose proper QAD with breakdown voltage
margin. 1~2 A current rating is enough in the 8W LED
bulb. As shown in Table 3, logic-level MOSFET with low
threshold voltage can additionally reduce power loss
because the regulated VAD is QAD threshold voltage.
Design Example
Figure 17 shows the design example of the active damper in
an 8W LED bulb system. As shown in Figure 18 and Figure
19, the delay by 80 kΩ RD and 100 nF CD is around 1ms.
During the delay, 220 Ω RAD dampens voltage and current
spike without current ringing or dimmer misfire.
3.3 Active Damper Diode (DD) Selection
80k
100nF
The active damper diode discharges CD to reset VGATE.
Diode with 1A rated forward current is enough to discharge
CD. Same as the QAD selection, maximum VAD at 90°
dimming angle and the highest input line voltage should be
checked first to select DD reverse voltage specification.
VGATE
ES1J
FQN1N50C
3.4 Active Damper Delay Circuit (RD, CD)
Selection
VAD
IIN
220/1W
The delay circuit (RD, CD) should create a long enough
delay time before QAD turns on to let RAD dampen the
current spike. The worst case for the spike current is 90°
dimming angle. Spike current ringing needs to be checked
first at 90° dimming angle to determine how long the spike
current is dampened. Then, adjust RD and CD to guarantee
the dampened period. The recommended CD and RD values
are hundreds of nF and tens of kΩ. If CD is too large and RD
is very small, DD cannot fully discharge CD in M4, as shown
in Figure 15.
CIN
VIN
Figure 17.Design Example: Active Damper in 8W Bulb
Figure 18.Measured Waveform at High Dimming Angle
Figure 19.Measured Waveform at Low Dimming Angle
© 2011 Fairchild Semiconductor Corporation
Rev. 1.0.2 • 10/11/12
www.fairchildsemi.com
6
AN-9745
APPLICATION NOTE
4. Features of FL7730
The FL7730 is an active power factor correction (PFC)
controller using single-stage flyback topology. Dimming
control with no flicker is implemented by the analog
sensing method. Primary-side regulation and single-stage
topology reduce external components, such as input bulk
capacitor and feedback circuitry to minimize cost. To
improve power factor and THD, constant on-time control is
utilized with an internal error amplifier and low bandwidth
compensator. Precise constant-current control regulates
accurate output current, independent of input voltage and
output voltage. Operating frequency is proportionally
adjusted by output voltage to guarantee DCM operation
with higher efficiency and simpler design. FL7730 provides
protections such as open-LED, short-LED, and over-
temperature protection.
Figure 20.Package Diagram
Table 4. Pin Definitions
Pin #
Name
Description
Current Sense. This pin connects a current-sense resistor to detect the MOSFET current for the
output-current regulation in constant-current regulation.
1
CS
2
3
4
5
GATE
GND
VDD
DIM
PWM Signal Output. This pin uses the internal totem-pole output driver to drive the power MOSFET.
Ground
Power Supply. IC operating current and MOSFET driving current are supplied using this pin.
Dimming. This pin controls the dimming operation of the LED lighting.
Voltage Sense. This pin detects the output voltage information and discharge time for linear frequency
control and constant-current regulation. This pin connects divider resistors from the auxiliary winding.
6
VS
7
8
COMI
GND
Constant-Current Loop Compensation. This pin is the output of the transconductance error amplifier.
Ground
Figure 21.Functional Block Diagram
© 2011 Fairchild Semiconductor Corporation
Rev. 1.0.2 • 10/11/12
www.fairchildsemi.com
7
AN-9745
APPLICATION NOTE
Design Summary
Figure 22 shows the schematic of the TRIAC dimmable LED driver using FL7730. This schematic is dedicated to low-line
voltage (90~140 VAC).
Q1
MB8S
D5
ES3D
L1
4.7mH
L2
4.7mH
VO
C3
100nF
R3
20k
R1
560/0.5W
C1
C8
10n
R11
510k
R12
510k
D1
ES1J
C2
330n
R17
51k
N1
N3
C10
C11
R10
100kΩ
0.5W
330n
Q2
FQN1N50C
R4
1M
35V/330uF 35V/1000uF
D4
R2
100/0.5W
F1
RS1M
1A/250V
D2 11V
R5
75k
D3
1N4003
R6 62k
R8
150k
R7
0
Q3 FL7730
C7
N2
5
6
47u
4
3
Dim
VDD
GND
C4 3.3u
VS
R13
Q4
FQU5N60C
10Ω
7
8
2
1
R9
20k
C5
10p
COMI GATE
C9
4.7nF
C6
2.2u
N.C
CS
R16
200Ω
R14
1.2Ω
R15
1.0Ω
Figure 22.Schematic of TRIAC Dimmable LED Driver Using FL7730 (Low Line: 90~140 VAC
)
NP2(3 4)
NA(2 6)
NS
(NS- NS+)
NP1(5 3)
Figure 23.Transformer Structure
Table 5. Winding Specifications
No
1
Winding
Pin (S → F)
5 3
Wire
Turns
Winding Method
NP1
0.13φ
38 Ts
Solenoid Winding
2
Insulation: Polyester Tape t = 0.025 mm, 2-Layer
NS- NS+ 0.3φ (TIW) 24 Ts
Insulation: Polyester Tape t = 0.025 mm, 2-Layer
2 6 0.13φ 18 Ts
Insulation: Polyester Tape t = 0.025 mm, 2-Layer
3 4 0.13φ 38 Ts
3
NS
NA
Solenoid Winding
Solenoid Winding
Solenoid Winding
4
5
6
7
NP2
8
Insulation: Polyester Tape t = 0.025 mm, 6-Layer
Table 6. Electrical Characteristics
Pin
Specification
Remark
Inductance
Leakage
1 – 2
1 – 2
1 mH ±10%
50 kHz, 1 V
50kHz, 1 V Short All Output Pins
8 µH
© 2011 Fairchild Semiconductor Corporation
Rev. 1.0.2 • 10/11/12
www.fairchildsemi.com
8
AN-9745
APPLICATION NOTE
Experimental Verification
The design example with passive bleeder and active damper
was experimentally verified in an 8 W LED lighting system.
Figure 24 shows constant current regulation at input voltage
and output voltage change. Constant-current deviation in
the wide output voltage range from 10 V to 28 V is less than
2.1% at each line input voltage. Line regulation at the rated
output voltage (22 V) is less than 3.9%.
Operation waveforms are shown in Figure 25, Figure 26,
and Figure 27. In this dimmable board, TRIAC dimmer
firing is stabilized without any misfire. FL7730 keeps
constant tON so VCS is in phase with VIN. The maximum
spike current of IIN is 1.2 A. Figure 28 shows the dimming
curve. RMS input voltage indicates TRIAC dimming angle.
LED current is smoothly controlled by the FL7730 dimming
function and external circuits, such as the passive bleeder
and active damper. Table 7 provides compatibility with
common dimmers for a design without visible flicker.
Maximum and minimum current vary because each
dimmer’s maximum and minimum angles are different.
Figure 25.Waveforms at Maximum Dimming Angle
IIN
VIN
System efficiency is from 80.7% to 82.9% at low line input
voltage (90 ~ 140 VAC). The active damper helps improve
the efficiency with a compact and inexpensive design
solution. Table 8 shows PF and THD in a low line input
voltage range of 90~140 VAC. PF is over 0.9 and THD is
much less than 30% by constant tON and linear frequency
control in the FL7730.
VCS
The performances obtained in the design example show a
powerful LED lighting solution with accurate constant
current regulation, stable dimming control, high efficiency,
high PF, and low THD with low BOM cost.
Figure 26.Waveforms at Half Dimming Angle
IIN
OVP
VIN
VCS
Figure 27.Waveforms at Minimum Dimming Angle
IOUT [mA]
Figure 24. CC Regulation, Measured by CR-Load
© 2011 Fairchild Semiconductor Corporation
Rev. 1.0.2 • 10/11/12
www.fairchildsemi.com
9
AN-9745
APPLICATION NOTE
Table 7. Dimmer Compatibility
Manufacturer
LUTRON
LUTRON
LUTRON
LUTRON
LUTRON
LUTRON
LUTRON
LEVITON
LEVITON
LEVITON
Legrand
Dimmer
Maximum Current
330 mA
Minimum Current
40 mA (12%)
11 mA (3.4%)
8 mA (2.2%)
12 mA (4.8%)
14 mA (4.2%)
3 mA (0.9%)
58 mA (18%)
36 mA (9.5%)
0 mA (0%)
Flicker
No
S-600P-WH
CN-600P-WH
GL-600H
328 mA
No
365 mA
No
TG-603PGH-WH
TG-600PH-WH
LG-600P
252 mA
No
333 mA
No
327 mA
No
CTCL-153PD
IP106
320 mA
No
380 mA
No
1C4005
344 mA
No
6631-LW
340 mA
0 mA (0%)
No
F 165H
344 mA
3 mA (0.9%)
No
Figure 29.Efficiency
Figure 28.Dimming Curve (Input Voltage vs.
LED Current)
Table 8. Power Factor (PF) and Total Harmonic Distortion (THD)
Input Voltage
90 VAC
Output Current
360 mA
Output Voltage
21.70 V
PF
THD
7.4%
0.98
0.96
0.95
0.91
110 VAC
376 mA
21.77 V
9.5%
120 VAC
380 mA
21.77 V
10.4%
12.4%
140 VAC
386 mA
21.79 V
© 2011 Fairchild Semiconductor Corporation
Rev. 1.0.2 • 10/11/12
www.fairchildsemi.com
10
AN-9745
APPLICATION NOTE
Related Datasheets
FL7730MY — Single-Stage Primary-Side-Regulation PWM Controller for PFC and LED Dimmable Driving
KA431 — Programmable Shunt Regulator
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APPLICATION OR USE OF ANY PRODUCT OR CIRCUIT DESCRIBED HEREIN; NEITHER DOES IT CONVEY ANY LICENSE UNDER ITS
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As used herein:
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(b) support or sustain life, or (c) whose failure to perform
when properly used in accordance with instructions for use
provided in the labeling, can be reasonably expected to
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© 2011 Fairchild Semiconductor Corporation
Rev. 1.0.2 • 10/11/12
www.fairchildsemi.com
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