CS8135YT5 [CHERRY]
5V, 5V Low Dropout Dual Regulator with /ENABLE RESET; 5V ， 5V低压降稳压器双用/ ENABLE RESET
| 型号： | CS8135YT5 |
| 厂家： | 
CHERRY SEMICONDUCTOR CORPORATION |
| 描述： | 5V, 5V Low Dropout Dual Regulator with /ENABLE RESET |
| 文件： | 总8页 (文件大小：184K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
CS8135
5V, 5V Low Dropout Dual Regulator
with
/ENABLE
RESET
Description
Features
The CS8135 is a low dropout, high cur-
transients, such as a 60V load dump,
the 500mA output will automatically
shut down the primary output to pro-
tect both internal circuits and the load.
The standby regulator will continue to
power any standby load.
■ Two Regulated Outputs
Primary Output 5V
± 5%; 500mA
rent, dual 5V linear regulator. The sec-
ondary 5V/10mA output is often used
for powering systems with standby
memory. Quiescent current drain is
less than 3mA when supplying 10mA
loads from the standby regulator.
Secondary Standby 5V
±5%; 10mA
■ Low Dropout Voltage
The CS8135 is packaged in a 5 lead
TO-220.
(0.6V at 0.5A)
In automotive applications, the CS8135
and all regulated circuits are protected
from reverse battery installations, as
well as two-battery jumps. During line
■ ON/OFF Control
NOTE: The CS8135 is compatible with
the LM2935.
Option
■ Low Quiescent Drain
(<3mA)
■ RESET Option
Absolute Maximum Ratings
■ Protection Features
Reverse Battery
Input Voltage
60V Load Dump
Operating Range.....................................................................-0.5V to 26V
Load Dump ............................................................................................60V
Internal Power Dissipation..................................................Internally Limited
Junction Temperature Range (TJ)............................................-40¡C to +150¡C
Storage Temperature Range ....................................................-65¡C to +150¡C
Lead Temperature Soldering
-50V Reverse Transient
Short Circuit
Thermal Shutdown
Overvoltage Shutdown
Wave Solder (through hole styles only)..........10 sec. max, 260¡C peak
Electrostatic Discharge (Human Body Model) ..........................................2kV
Package Option
Block Diagram
5 Lead TO-220
Standby Output
Tab (Gnd)
VIN
VOUT2
Output
Current
Limit
+
-
Bandgap
Reference
Primary Output
VOUT1
Gnd
Thermal
Shutdown
Over Voltage
Shutdown
Output
Current
Limit
+
-
+
RESET/
ENABLE
1 VIN
-
2 VOUT1
3 Gnd
1
RESET
4
/
+
-
ENABLE
5 VOUT2
Cherry Semiconductor Corporation
2000 South County Trail, East Greenwich, RI 02818
Tel: (401)885-3600 Fax: (401)885-5786
Email: info@cherry-semi.com
Web Site: www.cherry-semi.com
Rev. 10/21/97
A
¨
Company
1
Electrical Characteristics : VIN = 14V, IOUT1 = 5mA, IOUT2 = 1mA, -40¡C ² TA ² 125¡C, -40¡C ² TJ ² 150¡C unless otherwise specified
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX
UNIT
■ Output Stage (VOUT1
)
Output Voltage, VOUT1
Dropout Voltage
6V ² VIN ² 26V, 5mA ² IOUT1 ² 500mA
4.75
5.00
5.25
0.60
V
IOUT = 500mA
0.35
0.50
V
V
IOUT = 750mA
Line Regulation
Load Regulation
Quiescent Current
6V ² VIN ² 26V, IOUT1 = 5mA
5mA ² IOUT ² 500mA
10
10
50
50
mV
mV
IOUT1 ² 10mA, No Load on Standby
IOUT1 = 500mA, No Load on Standby
IOUT1 = 750mA, No Load on Standby
3
30
60
7
100
150
mA
mA
mA
Ripple Rejection
f = 120Hz
66
1.40
90
dB
A
Current Limit
0.75
Maximum Line Transient
VOUT1 ² 5.5V
V
Reverse Polarity
VOUT1 ³ -0.6V, 10½ Load
-50
V
Input Voltage, DC
Reverse Polarity Input
Voltage, Transient
1% Duty Cycle, t = 100ms, VOUT1 ³ -6V,
10½ Load
-80
V
Output Noise Voltage
Long Term Stability
Output Impedance
10Hz-100kHz
100
20
µVrms
mV/khr
m½
500mA DC and 10mA rms,
100Hz-10kHz
200
Overvoltage Shutdown
30
V
■ Standby Output (VOUT2
)
Output Voltage (VOUT2
Dropout Voltage
Tracking
)
6V ² VIN ² 26V, 1mA ² IOUT1 ² 10mA
IOUT2 = 10mA
4.75
5.00
0.3
50
4
5.25
0.7
200
50
V
V
VOUT1-VOUT2
mV
mV
mV
mA
dB
Line Regulation
Load Regulation
Quiescent Current
Ripple Rejection
Current Limit
6V ² VIN ² 26V
1mA ² IOUT1 ² 10mA
IOUT ² 10mA, VOUT OFF
f = 120Hz
10
2
50
3
66
70
300
20
1
25
mA
µV
Output Noise Voltage
Long Term Stability
Output Impedance
10Hz-100kHz
mV/khr
½
10mA DC and 1mA rms, 100Hz-10kHz
RESET
■
Function
RESET
Output Voltage
Low R1 = 20k½, VIN = 4.5V See Test & Application Circuit
0.8
5.0
1.1
6.0
V
V
High R1 = 20k½, VIN = 14V
(page 6)
4.5
RESET
Output Current
ON/OFF Resistor
VIN = 4.5V,
in Low State
5
mA
k½
RESET
R1 (±10% Tolerance)
20
30
2
Package Lead Description
LEAD SYMBOL
PACKAGE LEAD #
FUNCTION
TO-220
1
2
3
4
VIN
VOUT1
Supply voltage to IC, usually direct from battery.
Regulated output voltage 5V, 500mA (typ) switched.
Ground connection.
Gnd
RESET
goes low whenever
RESET/ENABLE
CMOS compatible output lead,
VOUT1 becomes unregulated. To use the ENABLE option, con-
nect the lead via a resistor to VIN (see app. notes).
5
VOUT2
STANDBY output 5V, 10mA typ, always on.
Typical Performance Characteristics
7
6
5
4
3
2
1
0
1.0
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0.0
R =500W
L
-1
-2
-40
-20
0
20
40
60
0
200
400
600
800
INPUT VOLTAGE (V)
OUTPUT CURRENT (mA)
Dropout Voltage vs. Output Current
Standby Output Voltage vs. Input Voltage
20
10
1.0
0.9
0.8
IOUT =500mA
1
0
-10
-20
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0.0
3
2
1
0
0
10
20
30
40
50
60
0
5
10
15
20
TIME (ms)
OUTPUT CURRENT (mA)
Standby Dropout Voltage vs. Output Current
Line Transient Response (VOUT1)
7
10
5
R =10W
L
6
5
4
3
2
1
0
0
-5
-10
3
2
1
-1
-2
0
-40
-20
0
20
40
60
0
10
20
30
40
50
60
INPUT VOLTAGE (V)
TIME (ms)
Output Voltage vs. Input Voltage
Line Transient Response (VOUT2
)
3
Typical Performance Characteristics: continued
150
100
50
5
SWITCH OPEN
VO OFF
4
0
-50
-100
-150
0.8
0.6
0.4
0.2
0
3
2
1
0
0
15
20
25
0
10
20
30
40
50
60
5
10
STANDBY OUTPUT CURRENT (mA)
TIME (ms)
Quiescent Current vs. Standby Output Current
Load Transient Response (VOUT1
)
20
150
100
50
18
INFINITE
HEAT SINK
16
0
14
12
10
8
-50
-100
-150
20
10° C/W HEAT SINK
6
4
15
10
NO HEAT SINK
2
0
5
0
0
10
20
30
40
50
60
70
80
90
0
10
20
30
40
50
60
AMBIENT TEMPERATURE (°C)
TIME (ms)
Maximum Power Dissipation (TO-220)
Load Transient Response (VOUT2
)
120
IOUT2=10mA
100
80
60
40
20
0
0
200
400
600
800
OUTPUT CURRENT (mA)
Quiescent Current vs. Output Current
4
Definition of Terms
Dropout Voltage
Long Term Stability
The input-output voltage differential at which the circuit
ceases to regulate against further reduction in input volt-
age. Measured when the output voltage has dropped
100mV from the nominal value obtained at 14V input,
dropout voltage is dependent upon load current and junc-
tion temperature.
Output voltage stability under accelerated life-test condi-
tions after 1000 hours with maximum rated voltage and
junction temperature.
Output Noise Voltage
The rms AC voltage at the output, with constant load and
no input ripple, measured over a specified frequency
range.
Input Voltage
The DC voltage applied to the input with respect to ground.
Quiescent Current
Input Output Differential
The part of the positive input current that does not con-
tribute to the positive load current. i.e., the regulator
ground lead current.
The voltage difference between the unregulated input
voltage and the regulated output voltage for which the
regulator will operate.
Ripple Rejection
The ratio of the peak-to-peak input ripple voltage to the
peak-to-peak output ripple voltage.
Line Regulation
The change in output voltage for a change in the input
voltage. The measurement is made under conditions of
low dissipation or by using pulse techniques such that the
average chip temperature is not significantly affected.
Temperature Stability of VOUT
The percentage change in output voltage for a thermal
variation from room temperature to either temperature
extreme.
Load Regulation
The change in output voltage for a change in load current
at constant chip temperature.
Current Limit
Peak current that can be delivered to the output.
Typical Circuit Waveform
60V
26V
14V
31V
VIN
14V
3V
SWITCH OPEN
OPEN
CLOSED
5V
5V
5V
5V
2.4V
0V
0V
VOUT
0V
1
5V
RESET
0V
5V
5V
5V
VOUT
2
2.4V
System
Condition
Turn
On
Load
Dump
Low VIN
Line, Noise, Etc.
VOUT1
Short
Thermal
Shutdown
Turn
Off
Circuit
*Reference Test & Application Circuit
Circuit Description
In applications where the standby output is not needed, it
may be disabled by connecting a resistor from the standby
output to the supply voltage. This eliminates the need for
a capacitor on the output to prevent unwanted oscilla-
tions. The value of the resistor depends upon the mini-
mum input voltage expected for a given system. Since the
standby output is shunted with an internal diode zener,
the current through the external resistor should be suffi-
cient to bias VOUT2 up to this point. Approximately 60µA
Standby Output
The CS8135 is equipped with two outputs. The second out-
put is intended for use in systems requiring standby mem-
ory circuits. While the high current regulator output can be
RESET
controlled with the
lead described below, the stand-
by output remains on under all conditions as long as suffi-
cient input voltage is applied to the IC. Thus, memory and
other circuits powered by this output remain unaffected by
positive line transients, thermal shutdown, etc.
will suffice, resulting in a 10k½ external resistor for most
applications.
The standby regulator circuit is designed so that the quies-
cent current to the IC is very low (<3mA) when the other
regulator output is off.
5
Circuit Description: continued
output voltage of this lead is high (5V). This is set by an
V
IN
internal clamp. If the high current output becomes unreg-
ulated for any reason (line transients, short circuit, thermal
shutdown, low input voltage, etc.) the lead switches to the
active low state, and is capable of sinking several mil-
liamps. This output signal can be used to initiate any reset
or start-up procedure that may be required of the system.
R
10kW
D
V
OUT2
V
OUT2
+
RESET
The
lead can also be driven directly from logic cir-
C
3
cuits. The only requirement is that the 20k½ pull-up resis-
tor remain in place. This will not affect the logic gate since
the voltage on this lead is limited by the internal clamp to
RESET
5V. The
signal is sacrificed in this arrangement
since the maximum sink capability of the lead in the active
low state (approximately 5mA), is usually not sufficient to
pull down the active high logic gate. The flag can be
retained if the driving gate is open collector logic.
Disabling VOUT2 when it is not needed. C3 is no longer needed.
High Current Output
V
IN
Unlike the standby regulated output, which must remain
on whenever possible, the high current regulated output is
fault protected against overvoltage and also incorporates
thermal shutdown. If the input voltage rises above approx-
imately 30V (e.g., load dump), this output will automatical-
ly shutdown. This protects the internal circuitry and
enables the IC to survive higher voltage transients than
would otherwise be expected. Thermal shutdown is effec-
tive against die overheating since the high current output
is the dominant source of power dissipation in the IC.
R1
20kW
CS8135
RESET/
ENABLE
Controlling ON/OFF Terminal with a typical CMOS or TTL Logic Gate
R1
20kW
CS8135
RESET Function
RESET/
CMOS MM 74CO4
or Equivalent
ENABLE
RESET
The
function has the ability to serve a dual purpose
R2
100kW
if desired. When controlled in the manner shown in the
test circuit (common in automotive systems where
Delayed
Reset
Out
Gnd
4.7 mF
RESET
/ENABLE is connected to the ignition switch), the
lead also serves as an output flag that is active low when-
ever a fault condition is detected with the high current
regulated output. Under normal operating conditions, the
Reset Pulse on Power-Up (with approximately 300ms delay)
Application Notes
Test & Application Circuit
Stability Considerations
The output or compensation capacitor helps determine
three main characteristics of a linear regulator: start-up
delay, load transient response and loop stability.
C1*
0.1 mF
The capacitor value and type should be based on cost,
availability, size and temperature constraints. A tantalum
or aluminum electrolytic capacitor is best, since a film or
ceramic capacitor with almost zero ESR, can cause insta-
bility. The aluminum electrolytic capacitor is the least
expensive solution, but, if the circuit operates at low tem-
peratures (-25¡C to -40¡C), both the value and ESR of the
capacitor will vary considerably. The capacitor manufac-
turers data sheet usually provides this information.
S1
ON/OFF
VIN
VOUT1
+
C2 **
10mF
R1
20kW
RESET
FLAG
RESET/
ENABLE
CS8135
VOUT2
Gnd
+
C3**
10mF
The value for output capacitor C2 shown in the test and
applications circuit should work for most applications,
however it is not necessarily the optimized solution.
NOTES:
* C1 required if regulator is located far from power supply filter.
** C2, C3 required for stability.
To determine acceptable values for C2 and C3 for a partic-
ular application, start with a tantalum capacitor of the rec-
6
Application Notes: continued
ommended value and work towards a less expensive
VOUT2(min) is the minimum output voltage from VOUT2,
alternative part for each output.
IOUT1(max) is the maximum output current for the
application,
Step 1: Place the completed circuit with the tantalum
capacitors of the recommended values in an environmen-
tal chamber at the lowest specified operating temperature
and monitor the outputs with an oscilloscope. A decade
box connected in series with capacitor C2 will simulate the
higher ESR of an aluminum capacitor. Leave the decade
box outside the chamber, the small resistance added by
the longer leads is negligible.
IOUT2(max) is the maximum output current, for the
application, and
IQ is the quiescent current the regulator consumes at
IOUT(max)
.
Once the value of PD(max) is known, the maximum permis-
sible value of RQJA can be calculated:
Step 2: With the input voltage at its maximum value,
increase the load current slowly from zero to full load on
the output under observation and look for oscillations on
the output. If no oscillations are observed, the capacitor is
large enough to ensure a stable design under steady state
conditions.
150¡C - TA
RQJA
=
(2)
PD
The value of RQJA can then be compared with those in
the package section of the data sheet. Those packages
with RQJA's less than the calculated value in equation 2
will keep the die temperature below 150¡C.
Step 3: Increase the ESR of the capacitor from zero using
the decade box and vary the load current until oscillations
appear. Record the values of load current and ESR that
cause the greatest oscillation. This represents the worst
case load conditions for the output at low temperature.
In some cases, none of the packages will be sufficient to
dissipate the heat generated by the IC, and an external
heatsink will be required.
Step 4: Maintain the worst case load conditions set in step
3 and vary the input voltage until the oscillations increase.
This point represents the worst case input voltage condi-
tions.
I
IN
I
I
OUT
1
2
V
Smart
Regulator
IN
V
V
OUT
1
2
Step 5: If the capacitor is adequate, repeat steps 3 and 4
with the next smaller valued capacitor. A smaller capaci-
tor will usually cost less and occupy less board space. If
the output oscillates within the range of expected operat-
ing conditions, repeat steps 3 and 4 with the next larger
standard capacitor value.
OUT
OUT
Control
Features
}
I
Q
Step 6: Test the load transient response by switching in
various loads at several frequencies to simulate its real
working environment. Vary the ESR to reduce ringing.
Figure 1: Dual output regulator with key performance parameters
labeled.
Step 7: Remove the unit from the environmental chamber
and heat the IC with a heat gun. Vary the load current as
instructed in step 5 to test for any oscillations.
Heat Sinks
A heat sink effectively increases the surface area of the
package to improve the flow of heat away from the IC and
into the surrounding air.
Once the minimum capacitor value with the maximum
ESR is found, a safety factor should be added to allow for
the tolerance of the capacitor and any variations in regula-
tor performance. Most good quality aluminum electrolytic
capacitors have a tolerance of ±20% so the minimum value
found should be increased by at least 50% to allow for this
tolerance plus the variation which will occur at low temper-
atures. The ESR of the capacitor should be less than 50% of
the maximum allowable ESR found in step 3 above.
Each material in the heat flow path between the IC and
the outside environment will have a thermal resistance.
Like series electrical resistances, these resistances are
summed to determine the value of RQJA
.
RQJA = RQJC + RQCS + RQSA
(3)
where
Repeat steps 1 through 7 with the capacitor on the other
output, C3.
R
R
R
QJC = the junction-to-case thermal resistance,
QCS = the case-to-heatsink thermal resistance, and
QSA = the heatsink-to-ambient thermal resistance.
Calculating Power Dissipation
in a Dual Output Linear Regulator
R
R
QJC appears in the package section of the data sheet. Like
QJA, it too is a function of package type. RQCS and RQSA
The maximum power dissipation for a dual output regu-
lator (Figure 1) is:
are functions of the package type, heatsink and the inter-
face between them. These values appear in heat sink data
sheets of heat sink manufacturers.
P
D(max) = {VIN(max)-VOUT1(min)}IOUT1(max)
+
{VIN(max)-VOUT2(min)}IOUT2(max)+VIN(max)IQ
(1)
Where
VIN(max) is the maximum input voltage,
VOUT1(min) is the minimum output voltage from VOUT1
,
7
Package Specification
Package Dimensions in MM (Inches)
5 Lead TO-220 (T) Straight
PACKAGE THERMAL DATA
5 Lead TO-220
Thermal Data
RQJC
typ
2.3
ûC/W
ûC/W
RQJA
typ
50
1.40 (.055)
1.14 (.045)
4.83 (.190)
5 Lead TO-220 (THA) Horizontal
10.54 (.415)
4.06 (.160)
9.78 (.385)
3.96 (.156)
4.83 (.190)
4.06 (.160)
2.87 (.113)
2.62 (.103)
3.71 (.146)
10.54 (.415)
9.78 (.385)
1.40 (.055)
1.14 (.045)
6.55 (.258)
5.94 (.234)
3.96 (.156)
3.71 (.146)
2.87 (.113)
2.62 (.103)
14.99 (.590)
14.22 (.560)
14.99 (.590)
14.22 (.560)
6.55 (.258)
5.94 (.234)
14.22 (.560)
13.72 (.540)
2.77 (.109)
6.83 (.269)
1.68
1.02 (.040)
0.76 (.030)
2.92 (.115)
2.29 (.090)
0.56 (.022)
(.066)
TYP
0.81(.032)
0.36 (.014)
0.56 (.022)
0.36 (.014)
1.83(.072)
1.57(.062)
1.02(.040)
0.63(.025)
6.60 (.260)
5.84 (.230)
1.70 (.067)
6.81(.268)
6.93(.273)
6.68(.263)
2.92 (.115)
2.29 (.090)
5 Lead TO-220 (TVA) Vertical
4.83 (.190)
4.06 (.160)
3.96 (.156)
3.71 (.146)
10.54 (.415)
9.78 (.385)
1.40 (.055)
1.14 (.045)
6.55 (.258)
5.94 (.234)
2.87 (.113)
2.62 (.103)
14.99 (.590)
14.22 (.560)
1.78 (.070)
2.92 (.115)
2.29 (.090)
8.64 (.340)
7.87 (.310)
4.34 (.171)
7.51 (.296)
0.56 (.022)
0.36 (.014)
1.68
(.066) typ
1.70 (.067)
6.80 (.268)
.94 (.037)
.69 (.027)
Ordering Information
Description
Part Number
CS8135YT5
CS8135YTVA5
CS8135YTHA5
Ch erry Sem icon du ctor Corporation reserves th e
righ t to m ake ch an ges to th e specification s with ou t
n otice. Please con tact Ch erry Sem icon du ctor
Corporation for th e latest available in form ation .
5 Lead TO-220 Straight
5 Lead TO-220 Vertical
5 Lead TO-220 Horizontal
Rev. 10/21/97
© 1999 Cherry Semiconductor Corporation
8
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