© Semiconductor Components Industries, LLC, 2003
April, 2021 − Rev. 3
1Publication Order Number:
LM431A/D
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
Figure 1. Block Diagram
TO−92
CASE 135AN
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See detailed ordering and shipping information in the package
dimensions section on page 6 of this data sheet.
ORDERING INFORMATION
MARKING DIAGRAM
PIN CONNECTIONS
LM431
XXXX
ALYW
LM431XXXX = Specific Device Code
A = Assembly Location
L = Wafer Lot
YW = Assembly Start Week
123
123
TO−92
CASE 135AR
123
1 − Ref
2 − Anode
3 − Cathode
123
LM431A, LM431B, LM431C
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2
ABSOLUTE MAXIMUM RATINGS
Symbol Parameter Value Unit
VKA Cathode Voltage 37 V
IKA Cathode Current Range (Continuous) −100 to +150 mA
IREF Reference Input Current Range −0.05 to +10 mA
PDPower Dissipation 770 mW
RθjA 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
TJJunction Temperature 150 °C
TSTG Storage Temperature Range −65 to +150 °C
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)
Symbol Parameter Conditions
LM431A LM431B LM431C
Unit
Min Typ Max Min Typ Max Min Typ Max
VREF Reference Input
Voltage
VKA = VREF
, IKA = 10 mA 2.450 2.500 2.550 2.470 2.495 2.520 2.482 2.495 2.508 V
DVREF/DTDeviation of
Reference Input
Voltage Over−
Temperature
VKA = VREF
, IKA =10 mA
TMIN ≤ TA ≤ TMAX (Note 1)
−4.5 17.0 −4.5 17.0 −4.5 17.0 mV
DVREF/
DVKA
Ratio of Change in
Reference Input
Voltage to the
Change in Cathode
Voltage
IKA = 10 mA 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
IREF Reference Input
Current
IKA = 10 mA, R1 = 10 kW,
R2 = ∞
−1.5 4.0 −1.5 4.0 −1.5 4.0 mA
DIREF/DTDeviation of
Reference Input
Current Over Full
Temperature Range
IKA = 10 mA, R1 = 10 kW,
R2 = ∞, TA = Full 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
ZKA 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
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
LM431A, LM431B, LM431C
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4
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
LM431A, LM431B, LM431C
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5
TYPICAL PERFORMANCE CHARACTERISTICS (Continued)
Figure 11. Stability Boundary Conditions
100p 1n 10n 100n 10u
0
20
40
60
80
100
120
140
D
C
B
A
A VKA = Vref
B V
KA = 5.0 V @ IK
C V
KA = 10 V @ IK
D V
KA = 15 V @ IK
= 10 mA
TA = 25oC
IK, CATHODE CURRENT(mA)
CL, LOAD CAPACITANCE
1u
= 10 mA
= 10 mA
LM431A, LM431B, LM431C
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6
TYPICAL APPLICATION
Figure 12. Shunt Regulator Figure 13. Output Control for Three−Terminal
Fixed Regulator
Figure 14. High−Current Shunt Regulator Figure 15. Current Limit or Current Source
Figure 16. Constant−Current Sink
IO+
VREF
RS
IO+
VREF
RCL
VO+ǒ1)
R1
R2Ǔ@VREF
VO+VREF @ǒ1)
R1
R2Ǔ
VO+ǒ1)
R1
R2Ǔ@VREF
LM431A
LM431A
LM431A
LM431A
LM431A
ORDERING INFORMATION
Part Number
Operating Temperature
Range
Output Voltage
Tolerance Tom Mark Package Packing Method†
LM431CCZ −25 ~ +85°C0.5% LM431CCZ TO−92 Bulk
LM431BCZX 1% LM431BCZ TO−92 Tape and Reel
LM431BCZXA LM431BCZ TO−92 Ammo
LM431ACZ 2% LM431ACZ TO−92 Bulk
LM431ACZX LM431ACZ TO−92 Tape and Reel
LM431BIZX −40 ~ +85°C1% LM431BIZ TO−92 Tape and Reel
LM431AIZ 2% LM431AIZ TO−92 Bulk
†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.
TO−92 3 4.825x4.76
CASE 135AN
ISSUE O
DATE 31 JUL 2016
MECHANICAL CASE OUTLINE
PACKAGE DIMENSIONS
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CASE 135AR
ISSUE O
DATE 30 SEP 2016
MECHANICAL CASE OUTLINE
PACKAGE DIMENSIONS
ON Semiconductor and are trademarks of Semiconductor Components Industries, LLC dba ON Semiconductor or its subsidiaries in the United States and/or other countries.
ON Semiconductor reserves the right to make changes without further notice to any products herein. ON Semiconductor makes no warranty, representation or guarantee regarding
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
disclaims any and all liability, including without limitation special, consequential or incidental damages. ON Semiconductor does not convey any license under its patent rights nor the
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