Programmable Shunt
Regulator
LM431A, LM431B, LM431C
Description
The LM431A/LM431B/LM431C are three−terminal output
adjustable regulators with thermal stability over the full operating
temperature range. The output voltage can be set to any value between
VREF (approximately 2.5 V) and 36 V with two external resistors.
These devices have a typical dynamic output impedance of 0.2 W.
Active output circuit provides a sharp turn−on characteristic, making
these devices excellent replacements for Zener diodes in many
applications.
Features
•
•
•
•
•
•
•
Programmable Output Voltage to 36 V
Low Dynamic Output Impedance: 0.2 W (Typical)
Sink Current Capability: 1.0 to 100 mA
Equivalent Full−Range Temperature Coefficient of 50 ppm/°C
(Typical)
Temperature Compensated for Operation Over Full Rated
Operating Temperature Range
Low Output Noise Voltage
Fast Turn−on Response
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12
1
3
2
3
TO−92
CASE 135AR
TO−92
CASE 135AN
MARKING DIAGRAM
LM431
XXXX
ALYW
LM431XXXX
A
L
YW
= Specific Device Code
= Assembly Location
= Wafer Lot
= Assembly Start Week
PIN CONNECTIONS
Figure 1. Block Diagram
1 − Ref
2 − Anode
3 − Cathode
1 2 3
1
2
3
ORDERING INFORMATION
See detailed ordering and shipping information in the package
dimensions section on page 6 of this data sheet.
© Semiconductor Components Industries, LLC, 2003
April, 2021 − Rev. 3
1
Publication Order Number:
LM431A/D
LM431A, LM431B, LM431C
ABSOLUTE MAXIMUM RATINGS
Symbol
Parameter
Value
Unit
37
V
VKA
Cathode Voltage
IKA
Cathode Current Range (Continuous)
−100 to +150
mA
IREF
Reference Input Current Range
−0.05 to +10
mA
Power Dissipation
770
mW
RθjA
PD
Thermal Resistance, Junction to Ambient
160
°C/W
TOPR
Operating Temperature Range − LM431xC
−25 to +85
°C
Operating Temperature Range − LM431xI
−40 to +85
°C
150
°C
−65 to +150
°C
TJ
TSTG
Junction Temperature
Storage Temperature Range
Stresses exceeding those listed in the Maximum Ratings table may damage the device. If any of these limits are exceeded, device functionality
should not be assumed, damage may occur and reliability may be affected.
RECOMMENDED OPERATING CONDITIONS
Symbol
Parameter
Min
Max
Unit
VKA
Cathode Voltage
VREF
36
V
IKA
Cathode Current
1.0
100
mA
Functional operation above the stresses listed in the Recommended Operating Ranges is not implied. Extended exposure to stresses beyond
the Recommended Operating Ranges limits may affect device reliability.
ELECTRICAL CHARACTERISTICS (Values are at TA = 25°C unless otherwise noted)
LM431A
Symbol
Parameter
Min
Conditions
VREF
Reference Input
Voltage
VKA = VREF, IKA = 10 mA
DVREF/DT
Deviation of
Reference Input
Voltage Over−
Temperature
VKA = VREF, IKA =10 mA
TMIN ≤ TA ≤ TMAX (Note 1)
Typ
LM431B
Max
Min
Typ
LM431C
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
17.0
−
4.5
17.0
−
4.5
17.0
mV
DVKA =
10 V−VREF
−
−1.0
−2.7
−
−1.0
−2.7
−
−1.0
−2.7
mV/V
DVKA =
36 V−10 V
−
−0.5
−2.0
−
−0.5
−2.0
−
−0.5
−2.0
IKA = 10 mA, R1 = 10 kW,
R2 = ∞
−
1.5
4.0
−
1.5
4.0
−
1.5
4.0
mA
Deviation of
IKA = 10 mA, R1 = 10 kW,
Reference Input
R2 = ∞, TA = Full Range
Current Over Full
Temperature Range
−
0.4
1.2
−
0.4
1.2
−
0.4
1.2
mA
IKA(MIN)
Minimum Cathode
Current for
Regulation
VKA = VREF
−
0.45
1.00
−
0.45
1.00
−
0.45
1.00
mA
IKA(OFF)
Off − Stage
Cathode Current
VKA = 36 V, VREF = 0
−
0.05
1.00
−
0.05
1.00
−
0.05
1.00
mA
Dynamic
Impedance
VKA = VREF, IKA = 1 to 100
mA,
f ≥ 1.0 kHz
−
0.15
0.50
−
0.15
0.50
−
0.15
0.50
W
DVREF/
DVKA
IREF
DIREF/DT
ZKA
Ratio of Change in IKA = 10 mA
Reference Input
Voltage to the
Change in Cathode
Voltage
Reference Input
Current
Product parametric performance is indicated in the Electrical Characteristics for the listed test conditions, unless otherwise noted. Product
performance may not be indicated by the Electrical Characteristics if operated under different conditions.
1. LM431xC: TMIN = −25°C, TMAX = +85°C
LM431xI: TMIN = −40°C, TMAX = +85°C
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2
LM431A, LM431B, LM431C
TEST CIRCUIT
LM431A
Figure 2. Test Circuit for VKA= VREF
LM431A
Figure 3. Test Circuit for VKA . VREF
LM431A
Figure 4. Test Circuit for IKA(OFF)
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3
LM431A, LM431B, LM431C
TYPICAL PERFORMANCE CHARACTERISTICS
Figure 5. Cathode Current vs. Cathode Voltage
Figure 6. Cathode Current vs. Cathode Voltage
Figure 7. Change in Reference Input
Voltage vs. Cathode Voltage
Figure 8. Dynamic Impedance Frequency
Figure 9. Small Signal Voltage Amplification
vs. Frequency
Figure 10. Pulse Response
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4
LM431A, LM431B, LM431C
TYPICAL PERFORMANCE CHARACTERISTICS (Continued)
140
A
IK, CATHODE CURRENT(mA)
120
100
A VKA = Vref
B VKA = 5.0 V @ I K = 10 mA
C VKA = 10 V @ I K = 10 mA
D VKA = 15 V @ IK = 10 mA
B
C
o
TA = 25 C
80
60
40
D
20
0
100p
1n
10n
100n
1u
10u
CL, LOAD CAPACITANCE
Figure 11. Stability Boundary Conditions
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5
LM431A, LM431B, LM431C
TYPICAL APPLICATION
LM431A
ǒ
VO + 1 )
R1
R2
Ǔ
LM431A
ǒ
@ V REF
V O + V REF @ 1 )
Figure 12. Shunt Regulator
ǒ
R1
R2
Ǔ
R2
Ǔ
Figure 13. Output Control for Three−Terminal
Fixed Regulator
LM431A
VO + 1 )
R1
LM431A
@ V REF
IO +
Figure 14. High−Current Shunt Regulator
V REF
R CL
Figure 15. Current Limit or Current Source
LM431A
IO +
V REF
RS
Figure 16. Constant−Current Sink
ORDERING INFORMATION
Part Number
Operating Temperature
Range
Output Voltage
Tolerance
Tom Mark
Package
Packing Method†
LM431CCZ
−25 ~ +85°C
0.5%
LM431CCZ
TO−92
Bulk
1%
LM431BCZ
TO−92
Tape and Reel
LM431BCZ
TO−92
Ammo
LM431ACZ
TO−92
Bulk
LM431ACZ
TO−92
Tape and Reel
1%
LM431BIZ
TO−92
Tape and Reel
2%
LM431AIZ
TO−92
Bulk
LM431BCZX
LM431BCZXA
LM431ACZ
2%
LM431ACZX
LM431BIZX
LM431AIZ
−40 ~ +85°C
†For information on tape and reel specifications, including part orientation and tape sizes, please refer to our Tape and Reel Packaging
Specifications Brochure, BRD8011/D.
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6
MECHANICAL CASE OUTLINE
PACKAGE DIMENSIONS
TO−92 3 4.825x4.76
CASE 135AN
ISSUE O
DOCUMENT NUMBER:
DESCRIPTION:
98AON13880G
TO−92 3 4.825X4.76
DATE 31 JUL 2016
Electronic versions are uncontrolled except when accessed directly from the Document Repository.
Printed versions are uncontrolled except when stamped “CONTROLLED COPY” in red.
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the suitability of its products for any particular purpose, nor does ON Semiconductor assume any liability arising out of the application or use of any product or circuit, and specifically
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MECHANICAL CASE OUTLINE
PACKAGE DIMENSIONS
TO−92 3 4.83x4.76 LEADFORMED
CASE 135AR
ISSUE O
DOCUMENT NUMBER:
DESCRIPTION:
98AON13879G
DATE 30 SEP 2016
Electronic versions are uncontrolled except when accessed directly from the Document Repository.
Printed versions are uncontrolled except when stamped “CONTROLLED COPY” in red.
TO−92 3 4.83X4.76 LEADFORMED
PAGE 1 OF 1
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are trademarks of Semiconductor Components Industries, LLC dba ON Semiconductor or its subsidiaries in the United States and/or other countries.
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the suitability of its products for any particular purpose, nor does ON Semiconductor assume any liability arising out of the application or use of any product or circuit, and specifically
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rights of others.
© Semiconductor Components Industries, LLC, 2019
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