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 0.2Ω 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
SOT-23F
3
1
1
2
1. Ref 2. Anode 3. Cathode 1. Cathode 2. Ref 3. Anode
SOT-23
3
1
2
M32 - 1. Ref 2. Cathode 3. Anode
M3 - 1. Cathode 2. Ref 3. Anode
Internal Block Diagram
+
-
© 2012 Fairchild Semiconductor Corporation
LM431SA/LM431SB/LM431SC Rev. 1.2.0
www.fairchildsemi.com
1
LM431SA/LM431SB/LM431SC — Programmable Shunt Regulator
June 2012
(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)
ML Suffix Package (SOT-89)
MF Suffix Package (SOT-23F)
M32, M3 Suffix Package (SOT-23)
RθJA
220
350
400
°
C/W
Power Dissipation (Note3,4)
ML Suffix Package (SOT-89)
MF Suffix Package (SOT-23F)
M32, M3 Suffix Package (SOT-23)
PD
Junction Temperature
TJ
150
°C
Operating Temperature Range
TOPR
-25 ~ +85
°C
Storage Temperature Range
TSTG
-65 ~ +150
°C
560
350
310
mW
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
Symbol
Min.
Typ.
Cathode Voltage
VKA
VREF
-
36
V
Cathode Current
IKA
1.0
-
100
mA
© 2012 Fairchild Semiconductor Corporation
LM431SA/LM431SB/LM431SC Rev. 1.2.0
Max.
Unit
www.fairchildsemi.com
2
LM431SA/LM431SB/LM431SC — Programmable Shunt Regulator
Absolute Maximum Ratings
(TA = +25°C, unless otherwise specified)
Parameter
Symbol
Reference
Input Voltage
VREF
Deviation of
Reference
Input Voltage
OverTemperature
ΔVREF/ΔT
VKA=VREF, IKA=10mA
SOT-89
VKA=VREF,
SOT-23F
IKA=10mA
TMIN≤TA≤TMAX
SOT-23
ΔVKA=10V
-VREF
Ratio of
Change in
Reference
Input Voltage
to the Change
in Cathode
Voltage
ΔVREF/
ΔVKA
Reference
Input Current
IREF
Deviation of
Reference
Input Current
Over Full
Temperature
Range
Conditions
IKA =10mA
ΔVKA=36V
-10V
ΔIREF/ΔT
IKA=10mA,
R1=10KΩ,R2=∞
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
Unit
V
-
4.5
17
-
4.5
17
-
4.5
17
mV
-
6.6
24
-
6.6
24
-
6.6
24
mV
-
-1.0
-2.7
-
-1.0
-2.7
-
-1.0
-2.7
-
-0.5
-2.0
-
-0.5
-2.0
-
-0.5
-2.0
-
1.5
4
-
1.5
4
-
1.5
4
μA
mV/V
SOT-89
SOT-23F
IKA=10mA,
R1=10KΩ,
R2=∞,
TA =Full Range SOT-23
-
0.4
1.2
-
0.4
1.2
-
0.4
1.2
μA
-
0.8
2.0
-
0.8
2.0
-
0.8
2.0
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
Note1
TMIN = -25°C, TMAX = +85°C
© 2012 Fairchild Semiconductor Corporation
LM431SA/LM431SB/LM431SC Rev. 1.2.0
www.fairchildsemi.com
3
LM431SA/LM431SB/LM431SC — Programmable Shunt Regulator
Electrical Characteristics
LM431S
LM431S
Figure 2. Test Circuit for VKA≥VREF
Figure 1. Test Circuit for VKA=VREF
LM431S
Figure 3. Test Circuit for lKA(OFF)
© 2012 Fairchild Semiconductor Corporation
LM431SA/LM431SB/LM431SC Rev. 1.2.0
www.fairchildsemi.com
4
LM431SA/LM431SB/LM431SC — Programmable Shunt Regulator
Test Circuits
800
150
VKA = VREF
VKA = VREF
o
TA = 25 C
o
TA = 25 C
600
IKA, CATHODE CURRENT (uA)
IK, Cathode Current (mA)
100
50
0
IKA(MIN)
400
200
-50
0
-100
-2
-1
0
1
2
-200
3
-1
0
1
VKA, Cathode Voltage (V)
2
3
VKA, CATHODE VOLTAGE (V)
Figure 4. Cathode Current vs. Cathode Voltage
Figure 5. Cathode Current vs. Cathode Voltage
0.20
3.5
3.0
0.16
Iref, Reference Input Current (uA)
Ioff, Off-State Cathode Current (uA)
0.18
0.14
0.12
0.10
0.08
0.06
0.04
2.5
2.0
1.5
1.0
0.5
0.02
0.00
-50
0.0
-50
-25
0
25
50
75
100
125
-25
0
25
50
150
75
100
125
o
TA, Ambient Temperature ( C)
o
TA, Ambient Temperature ( C)
Figure 6. OFF-State Cathode Current vs.
Ambient Temperature
Figure 7. 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
0
10M
Figure 8. Small Signal Voltage Amplification vs.
Frequency
8
12
16
20
Figure 9. Pulse Response
© 2012 Fairchild Semiconductor Corporation
LM431SA/LM431SB/LM431SC Rev. 1.2.0
4
Time (us)
Frequency (Hz)
www.fairchildsemi.com
5
LM431SA/LM431SB/LM431SC — Programmable Shunt Regulator
Typical Performance Characteristics
5
140
A VKA = Vref
B VKA = 5.0 V @ IK = 10mA
120
4
o
A
100
Current(mA)
IK, CATHODE CURRENT(mA)
TA = 25 C
80
stable
stable
60
3
2
40
1
20
B
0
100p
1n
10n
1ٛ
100n
0
0.0
10ٛ
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
2.0
Anode-Ref. Voltage(V)
CL, LOAD CAPACITANCE
Figure 10. Stability Boundary Conditions
Figure 11. Anode-Reference Diode Curve
5
Current(mA)
4
3
2
1
0
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
2.0
Ref.-Cathode Voltage(V)
Figure 12. Reference-Cathode Diode Curve
© 2012 Fairchild Semiconductor Corporation
LM431SA/LM431SB/LM431SC Rev. 1.2.0
www.fairchildsemi.com
6
LM431SA/LM431SB/LM431SC — Programmable Shunt Regulator
Typical Performance Characteristics (Continued)
LM431SA/LM431SB/LM431SC — Programmable Shunt Regulator
Typical Application
R1
V O = V ref ⎛ 1 + -------⎞
⎝
R 2⎠
R1
V O = ⎛ 1 + -------⎞ V ref
⎝
R 2⎠
LM7805/MC7805
LM431S
LM431S
Figure 14. Output Control for
Three-Terminal Fixed Regulator
Figure 13. Shunt Regulator
R1
V O = ⎛⎝ 1 + -------⎞⎠ V ref
R2
LM431S
Figure 15. High Current Shunt Regulator
LM431S
LM431S
Figure 16. Current Limit or Current Source
Figure 17. Constant-Current Sink
© 2012 Fairchild Semiconductor Corporation
LM431SA/LM431SB/LM431SC Rev. 1.2.0
www.fairchildsemi.com
7
Package
Dimensions in millimeters
SOT-89
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Marking
43A
2% tolerance
43B
43C
1% tolerance
0.5% tolerance
© 2012 Fairchild Semiconductor Corporation
LM431SA/LM431SB/LM431SC Rev. 1.2.0
www.fairchildsemi.com
8
LM431SA/LM431SB/LM431SC — Programmable Shunt Regulator
Mechanical Dimensions
Package
Dimensions in millimeters
SOT-23F
Marking
43A
43B
2% tolerance
1% tolerance
© 2012 Fairchild Semiconductor Corporation
LM431SA/LM431SB/LM431SC Rev. 1.2.0
43C
0.5% tolerance
www.fairchildsemi.com
9
LM431SA/LM431SB/LM431SC — Programmable Shunt Regulator
Mechanical Dimensions (Continued)
Package
Dimensions in millimeters
SOT-23
Marking
43G
43H
2% tolerance
1% tolerance
43L
43M
2% tolerance
1% tolerance
M32 -
M3 -
© 2012 Fairchild Semiconductor Corporation
LM431SA/LM431SB/LM431SC Rev. 1.2.0
43J
0.5% tolerance
43N
0.5% tolerance
www.fairchildsemi.com
10
LM431SA/LM431SB/LM431SC — Programmable Shunt Regulator
Mechanical Dimensions (Continued)
Product Number Output Voltage Tolerance Operating Temperature Package Packing Method
LM431SCCMLX
LM431SCCMFX
LM431SCCM32X
SOT-89
SOT-23F
0.5%
SOT-23
LM431SCCM3X
SOT-23
LM431SBCMLX
SOT-89
LM431SBCMFX
LM431SBCM32X
1%
-25 ~ +85°C
SOT-23F
SOT-23
LM431SBCM3X
SOT-23
LM431SACMLX
SOT-89
LM431SACMFX
LM431SACM32X
Tape and Reel
SOT-23F
2%
SOT-23
LM431SACM3X
SOT-23
Note : X suffix means " Tape and Reel " packing.
© 2012 Fairchild Semiconductor Corporation
LM431SA/LM431SB/LM431SC Rev. 1.2.0
www.fairchildsemi.com
11
LM431SA/LM431SB/LM431SC — Programmable Shunt Regulator
Ordering Information
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Datasheet contains the design specifications for product development. Specifications may change
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Datasheet contains preliminary data; supplementary data will be published at a later date. Fairchild
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Rev. I61
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