Fairchild LM431 Programmable shunt regulator Datasheet

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LM431SA/LM431SB/LM431SC
Programmable Shunt Regulator
Features
Description
•
•
•
•
The LM431SA/LM431SB/LM431SC are three terminal
output adjustable regulators with thermal stability over
operating temperature range. The output voltage can be set
any value between VREF (approximately 2.5 volts) and 36
volts with two external resistors. These devices have a
typical dynamic output impedance of 0.2Ω Active output
circuit provides a sharp turn-on characteristic, making these
devices excellent replacement for Zener Diodes in many
applications.
Programmable Output Voltage to 36 Volts
Low Dynamic Output Impedance 0.20 Typical
Sink Current Capability of 1.0 to 100mA
Equivalent Full-Range Temperature Coefficient of
50ppm/°C Typical
• Temperature Compensated for Operation Over Full Rated
Operating Temperature Range
• Low Output Noise Voltage
• Fast Turn-on Response
SOT-89
1
1. Ref 2. Anode 3. Cathode
SOT-23F
3
1
2
1. Cathode 2. Ref 3. Anode
Internal Block Diagram
Rev. 1.0.3
©2002 Fairchild Semiconductor Corporation
LM431SA/LM431SB/LM431SC
Absolute Maximum Ratings
(Operating temperature range applies unless otherwise specified.)
Parameter
Symbol
Value
Unit
Cathode Voltage
VKA
37
V
Cathode current Range (Continuous)
IKA
-100 ~ +150
mA
Reference Input Current Range
IREF
0.05 ~ +10
mA
Thermal Resistance Junction-Air (Note1,2)
MF Suffix Package
ML Suffix Package
RθJA
350
220
°C/W
Power Dissipation (Note3,4)
MF Suffix Package
ML Suffix Package
PD
350
560
mW
Junction Temperature
TJ
150
°C
Operating Temperature Range
TOPR
-25 ~ +85
°C
Storage Temperature Range
TSTG
-65 ~ +150
°C
Note:
1. Thermal resistance test board
Size: 76.2mm * 114.3mm * 1.6mm (1S0P)
JEDEC Standard: JESD51-3, JESD51-7
2. Assume no ambient airflow.
3. TJMAX = 150°C, Ratings apply to ambient temperature at 25°C
4. Power dissipation calculation: PD = (TJ - TA)/RθJA
Recommended Operating Conditions
Parameter
2
Symbol
Min.
Typ.
Max.
Unit
Cathode Voltage
VKA
VREF
-
36
V
Cathode Current
IKA
1.0
-
100
mA
LM431SA/LM431SB/LM431SC
Electrical Characteristics
(TA = +25°C, unless otherwise specified)
Parameter
Symbol
Reference
Input Voltage
VREF
VKA=VREF, IKA=10mA
∆VREF/
∆T
VKA=VREF, IKA=10mA
TMIN≤TA≤TMAX
Deviation of
Reference
Input Voltage
OverTemperature
Ratio of
Change in
Reference
Input Voltage
to the Change
in Cathode
Voltage
∆VREF/
∆VKA
Conditions
IKA
=10mA
∆VKA=10VVREF
LM431SA
LM431SB
LM431SC
Min. Typ. Max. Min. Typ. Max. Min. Typ. Max.
2.450 2.500 2.550 2.470 2.495 2.520 2.482 2.495 2.508
-
-
4.5
17
-1.0
-2.7
-
-
4.5
17
-1.0
-2.7
-
-
4.5
17
-1.0
-2.7
Unit
V
mV
mV/V
∆VKA=36V10V
-
-0.5
-2.0
-
-0.5
-2.0
-
-0.5
-2.0
IKA=10mA,
R1=10KΩ,R2=∞
-
1.5
4
-
1.5
4
-
1.5
4
µA
Deviation of
Reference
Input Current
Over Full
Temperature
Range
IKA=10mA,
R1=10KΩ,R2=∞
∆IREF/∆T
TA =Full Range
-
0.4
1.2
0.4
1.2
0.4
1.2
µA
Minimum
Cathode
Current for
Regulation
IKA(MIN)
VKA=VREF
-
0.45
1.0
-
0.45
1.0
-
0.45
1.0
mA
Off -Stage
Cathode
Current
IKA(OFF)
VKA=36V, VREF=0
-
0.05
1.0
-
0.05
1.0
-
0.05
1.0
µA
Dynamic
Impedance
ZKA
VKA=VREF,
IKA=1 to 100mA ,f ≥1.0kHz
-
0.15
0.5
-
0.15
0.5
-
0.15
0.5
Ω
Reference
Input Current
IREF
-
-
Note1
TMIN = -25°C, TMAX = +85°C
3
LM431SA/LM431SB/LM431SC
Test Circuits
LM431S
LM431S
Figure 1. Test Circuit for VKA=VREF
LM431S
Figure 3. Test Circuit for lKA(OFF)
4
Figure 2. Test Circuit for VKA≥VREF
LM431SA/LM431SB/LM431SC
Typical Performance Characteristics
800
150
VKA = VREF
o
VKA = V REF
TA = 25 C
o
T A = 25 C
600
IKA, CATHODE CURRENT (uA)
IK, Cathode Current (mA)
100
50
0
400
I KA(MIN)
200
0
-50
-200
-100
-2
-1
0
1
2
-1
3
0
1
2
3
V KA, CATHODE VOLTAGE (V)
VKA, Cathode Voltage (V)
Figure 4. Cathode Current vs. Cathode Voltage
Figure 5. Cathode Current vs. Cathode Voltage
3.5
0.100
Iref, Reference Input Current (uA)
Ioff, Off-State Cathode Current (uA)
3.0
0.075
0.050
0.025
0.000
-50
-25
0
25
50
75
100
2.5
2.0
1.5
1.0
0.5
0.0
-50
125
-25
0
o
25
50
75
100
125
o
TA, Ambient Temperature ( C)
TA, Ambient Temperature ( C)
Figure 6. OFF-State Cathode Current vs.
Ambient Temperature
Figure7. Reference Input Current vs.
Ambient Temperature
6
60
o
TA = 25 C
IKA = 10mA
50
o
TA=25 C
5
INPUT
4
Voltage Swing (V)
Open Loop Voltage Gain (dB)
40
30
20
3
OUTPUT
2
10
1
0
0
-10
1k
10k
100k
1M
10M
Frequency (Hz)
Figure 8. Small Signal Voltage Amplification vs. Frequency
0
4
8
12
16
20
Time (us)
Figure 9. Pulse Response
5
LM431SA/LM431SB/LM431SC
Typical Performance Characteristics (Continued)
5
140
4
A V KA = Vref
B V KA = 5.0 V @ IK = 10mA
120
o
A
100
Current(mA)
IK, CATHODE CURRENT(mA)
T A = 25 C
80
60
1
B
0
100p
1n
10n
100n
1µ
10µ
CL, LOAD CAPACITANCE
5
Current(mA)
4
3
2
1
0.2
0.4
0.6
0.8
1.0
1.2
1.4
0
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
2.0
Anode-Ref. Voltage(V)
Figure 10. Stability Boundary Conditions
1.6
1.8
2.0
Ref.-Cathode Voltage(V)
Figure 12. Reference-Cathode Diode Curve
6
2
40
20
0
0.0
3
Figure 11. Anode-Reference Diode Curve
LM431SA/LM431SB/LM431SC
Typical Application
R
V O = V ref  1 + ------1-
R2
R
V O =  1 + ------1- V ref

R 
2
R
V O =  1 + ------1- V ref

R 
2
LM7805/MC7805
LM431S
LM431S
Figure 13. Shunt Regulator
-
LM431S
Figure 14. Output Control for
Figure 15. High Current Shunt Regulator
Three-Termianl Fixed Regulator
LM431S
Figure 16. Current Limit or Current Source
LM431S
Figure 17. Constant-Current Sink
7
LM431SA/LM431SB/LM431SC
Mechanical Dimensions
Package
Dimensions in millimeters
SOT-23F
Marking
8
43A
43B
2% tolerance
1% tolerance
43C
0.5% tolerance
LM431SA/LM431SB/LM431SC
Mechanical Dimensions (Continued)
Package
Dimensions in millimeters
SOT-89
1.50 ±0.20
4.50 ±0.20
(0.40)
(1.10)
2.50 ±0.20
C0.2
4.10 ±0.20
(0.50)
1.65 ±0.10
0.50 ±0.10
0.40 ±0.10
0.40
+0.10
–0.05
1.50 TYP 1.50 TYP
Marking
43A
2% tolerance
43B
43C
1% tolerance
0.5% tolerance
9
LM431SA/LM431SB/LM431SC
Ordering Information
Product Number
LM431SCCML
LM431SCCMF
LM431SBCML
LM431SBCMF
LM431SACML
LM431SACMF
Output Voltage Tolerance
0.5%
1%
2%
Package
Operating Temperature
SOT-89
SOT-23F
SOT-89
SOT-23F
-25 ~ +85°C
SOT-89
SOT-23F
DISCLAIMER
FAIRCHILD SEMICONDUCTOR RESERVES THE RIGHT TO MAKE CHANGES WITHOUT FURTHER NOTICE TO ANY
PRODUCTS HEREIN TO IMPROVE RELIABILITY, FUNCTION OR DESIGN. FAIRCHILD DOES NOT ASSUME ANY
LIABILITY ARISING OUT OF THE APPLICATION OR USE OF ANY PRODUCT OR CIRCUIT DESCRIBED HEREIN; NEITHER
DOES IT CONVEY ANY LICENSE UNDER ITS PATENT RIGHTS, NOR THE RIGHTS OF OTHERS.
LIFE SUPPORT POLICY
FAIRCHILD’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES
OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT OF FAIRCHILD SEMICONDUCTOR
CORPORATION. As used herein:
1. Life support devices or systems are devices or systems
which, (a) are intended for surgical implant into the body,
or (b) support or sustain life, and (c) whose failure to
perform when properly used in accordance with
instructions for use provided in the labeling, can be
reasonably expected to result in a significant injury of the
user.
2. A critical component in 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.
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