© Semiconductor Components Industries, LLC, 2018
March, 2021 − Rev. 9
1Publication Order Number:
LM431SA/D
Programmable Shunt
Regulator
LM431SA, LM431SB,
LM431SC
Description
The LM431SA / LM431SB / LM431SC are three−terminal the
output adjustable regulators with thermal stability over operating
temperature range. The output voltage can be set 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 replacement 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
•These Devices are Pb−Free, Halogen Free/BFR Free and are RoHS
Compliant
ORDERING INFORMATION
Product Number
Output Voltage
Tolerance
Operating
Temperature Top Mark(1) Package Shipping†
LM431SACMFX 2% −25 to +85_C43A □SOT−23FL 3L Tape and Reel
LM431SACM3X 43L ◎SOT−23 3L
LM431SACM32X 43G ◎SOT−23 3L
LM431SBCMLX 1% 43B SOT−89 3L
LM431SBCMFX 43B □SOT−23FL 3L
LM431SBCM3X 43M ◎SOT−23 3L
LM431SBCM32X 43H ◎SOT−23 3L
LM431SCCMLX 0.5% 43C SOT−89 3L
LM431SCCMFX 43C □SOT−23FL 3L
LM431SCCM3X 43N ◎SOT−23 3L
LM431SCCM32X 43J ◎SOT−23 3L
LM431SAIMFX 2% −40 to +85_C43AI SOT−23FL 3L
LM431SBIMFX 1% 43BI SOT−23FL 3L
LM431SCIMFX 0.5% 43CI SOT−23FL 3L
†For information on tape and reel specifications, including part orientation and tape sizes, please refer to our Tape and Reel Packaging
Specification Brochure, BRD8011/D.
1. SOT−23 and SOT−23FL have basically four−character marking except LM431SAIMFX. (3 letters for device code + 1 letter for date code)
SOT−23FL date code is composed of 1 digit numeric or alphabetic week code adding bar−type year code.
www.onsemi.com
SOT−89
CASE 528AH
1
12
3
SOT−23FL
CASE 318AB
SOT−23
CASE 318BM
12
3
1. Ref
2. Anode
3. Cathode
1. Cathode
2. Ref
3. Anode
M32
1. Ref
2. Cathode
3. Anode
M3
1. Cathode
2. Ref
3. Anode
LM431SA, LM431SB, LM431SC
www.onsemi.com
2
Block Diagram
Figure 1. Block Diagram
ABSOLUTE MAXIMUM RATINGS (TA = 25°C unless otherwise noted)
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 +10.00 mA
RθJA
Thermal Resistance Junction−Air (2, 3)
ML Suffix Package (SOT−89) 220 °C/W
MF Suffix Package (SOT−23FL) 350
M32, M3 Suffix Package (SOT−23) 400
PDPower Dissipation (4, 5) ML Suffix Package (SOT−89) 560 mW
MF Suffix Package (SOT−23FL) 350
M32, M3 Suffix Package (SOT−23) 310
TJJunction Temperature 150 °C
TOPR Operating Temperature Range All products except LM431SAIMFX −25 to +85 °C
LM431SAIMFX, SBIMFX, SCIMFX −40 to +85
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.
2. Thermal resistance test board
Size: 1.6 mm x 76.2 mm x 114.3 mm (1S0P) JEDEC Standard: JESD51−3, JESD51−7.
3. Assume no ambient airflow.
4. TJMAX = 150°C; ratings apply to ambient temperature at 25°C.
5. Power dissipation calculation: PD = (TJ − TA) / RθJA.
RECOMMENDED OPERATING CONDITIONS
Symbol Parameter Min. Max. Unit
VKA Cathode Voltage VREF 36 V
IKA Cathode Current 1 100 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.
LM431SA, LM431SB, LM431SC
www.onsemi.com
3
ELECTRICAL CHARACTERISTICS (Note 6, Values are at TA = 25°C unless otherwise noted)
Symbol Parameter Conditions
LM431SA LM431SB LM431SC
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 / DT
Deviation of Refer-
ence Input Voltage
Over− Tempera-
ture
VKA = VREF,
IKA = 10 mA
TMIN ≤ TA ≤TMAX
SOT−89
SOT−23FL 4.5 17.0 4.5 17.0 4.5 17.0 mV
SOT−23 6.6 24 6.6 24 6.6 24 mV
DVREF /
DVKA
Ratio of Change in
Reference Input
Voltage to the
Change in Cath-
ode 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 μA
DIREF / DT
Deviation of Refer-
ence Input Current
Over Full Temper-
ature Range
IKA = 10 mA,
R1 = 10 KW,
R2 = ∞,
TA = Full Range
SOT−89
SOT−23FL 0.4 1.2 0.4 1.2 0.4 1.2 μA
SOT−23 0.8 2.0 0.8 2.0 0.8 2.0 μA
IKA(MIN) Minimum Cathode
Current for Regu-
lation
VKA = VREF 0.45 1.00 0.45 1.00 0.45 1.00 mA
IKA(OFF) Off −Stage Cath-
ode Current VKA = 36 V, VREF = 0 0.05 1.00 0.05 1.00 0.05 1.00 μA
ZKA Dynamic Imped-
ance
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.
6. LM431SAI, LM431SBI, LM431SCI: − TA(min) = −40_C, TA(max) = +85_C
All other pins: − TA(min) = −25_C, TA(max) = +85_C
LM431SA, LM431SB, LM431SC
www.onsemi.com
4
ELECTRICAL CHARACTERISTICS (Continued) (Notes 7 and 8, Values are at TA = 25°C unless otherwise noted)
Symbol Parameter Conditions
LM431SAI LM431SBI LM431SCI
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
VREF(dev)
Deviation of Refer-
ence Input Voltage
Over−Temperature
VKA = VREF
, IKA = 10 mA, TMIN ≤ TA ≤
TMAX 5 20 5 20 5 20 mV
DVREF /
DVKA
Ratio of Change in
Reference Input Volt-
age to 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 μA
IREF(dev)
Deviation of Refer-
ence Input Current
Over Full Temperature
Range
IKA = 10 mA, R1 = 10 KW, R2 = ∞,
TMIN ≤ TA ≤TMAX
0.8 2.0 0.8 2.0 0.8 2.0 μA
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 μA
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
7. LM431SAI, LM431SBI, LM431SCI: − TA(min) = −40_C, TA(max) = +85_C
All other pins: − TA(min) = −25_C, TA(max) = +85_C
8. The deviation parameters VREF(dev) and IREF(dev)are defined as the differences between the maximum and minimum values obtained over the
rated temperature range. The average full−range temperature coefficient of the reference input voltage, αVREF
, is defined as:
|aVREF|ǒppm
°CǓ+ǒVREF(dev)
VREF(at 25°C)Ǔ@106
TMAX *TMIN
VREF(min)
VREF(max)
TMAX -TMIN
VREF(dev)
where TMAX −TMIN is the rated operating free−air temperature range
of the device.
aVREF can be positive or negative, depending on whether minimum
VREF or maximum VREF
, respectively, occurs at the lower
temperature.
Example:
VREF(dev) = 4.5 mV, VREF = 2500 mV at 25°C,
TMAX −TMIN = 125°C for LM431SAI.
|aVREF|+ǒ4.5 mV
2500 mVǓ@106
125°C+14.4 ppmń°C
Because minimum VREF occurs at the lower temperature, the
coefficient is positive.
LM431SA, LM431SB, LM431SC
www.onsemi.com
6
TYPICAL APPLICATIONS
VO+ǒ1)R1
R2ǓVref
Figure 5. Shunt Regulator
LM431S
VO+ǒ1)R1
R2ǓVref
Figure 6. Output Control for Three−Terminal Fixed
Regulator
LM431S
LM7805/MC7805
VO+ǒ1)R1
R2ǓVref
Figure 7. High Current Shunt Regulator
LM431S
Figure 8. Current Limit or Current Source
LM431S
Figure 9. Constant−Current Sink
LM431S
LM431SA, LM431SB, LM431SC
www.onsemi.com
7
TYPICAL PERFORMANCE CHARACTERISTICS
Figure 10. Cathode Current vs. Cathode Voltage
−2−10 1 2 3
−100
−50
0
50
100
150
IK, Cathode Current (mA)
VKA, Cathode Voltage (V)
IK − Cathode Current (mA)
VKA − Cathode Voltage (V)
VKA = VREF
TA = 25°C
100
Figure 11. Cathode Current vs. Cathode Voltage
VKA − Cathode Voltage (V)
IK − Cathode Current (mA)
VKA = VREF
TA = 25°C
−200
0
200
400
600
800
IKA(MIN)
−10123
Figure 12. OFF−State Cathode Current vs. Ambient
Temperature
−50
0.00
0.02
0.04
0.06
0.08
0.10
0.12
0.14
0.16
0.18
0.20
TA
, Ambient Temperature (
oC)
−25 0 25 50 75 100 125 150
TA − Ambient Temperature (°C)
Ioff − Off−State Cathode
Current (mA)
Figure 13. Reference Input Current vs. Ambient
Temperature
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
−50 −25 0 25 50 75 100 125
TA − Ambient Temperature (°C)
Iref − Reference Input
Current (mA)
Figure 14. Frequency vs. Small Signal Voltage
Amplification
1k 10k 100k 1M 10M
−10
0
10
20
30
40
50
60
Frequency (Hz)
Frequency (Hz)
Open Loop Voltage Gain (dB)
TA = 25°C
IKA = 10 mA
Figure 15. Pulse Response
Voltage Swing (V)
0
1
2
3
4
5
6
048121620
Time (ms)
OUTPUT
INPUT
TA = 25°C
LM431SA, LM431SB, LM431SC
www.onsemi.com
8
Figure 16. Stability Boundary Conditions
100p 1n 10n 100n 1? 10?
0
20
40
60
80
100
120
140
B
A
CL − Load Capacitance
IK − Cathode Current (mA)
A. VKA = Vref
B. VKA = 5.0 V @ IK = 10 mA
TA = 25°C
Figure 17. Anode−Reference Diode Curve
0.0
0
1
2
3
4
5
Anode−Ref. Voltage(V)
Current (mA)
Anode−Ref. Voltage (V)
0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0
Figure 18. Reference−Cathode Diode Curve
0
1
2
3
4
5
Cu rrent(mA)
Ref.−Cathode Voltage(V)
Ref.−Cathode Voltage (V)
Current (mA)
0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0
Figure 19. Reference Input Voltage vs. Ambient
Temperature
2.46
2.47
2.48
2.49
2.50
2.51
−50 −25 0 25 50 75 100 125
TA − Ambient Temperature (°C)
Vref − Reference Input
Voltage (V)
SOT23−FL3L
CASE 318AB
ISSUE O
DATE 11 DEC 2020
1
XXXM
XXX = Specific Device Code
M = Date Code
GENERIC
MARKING DIAGRAM*
*This information is generic. Please refer to
device data sheet for actual part marking.
Pb−Free indicator, “G” or microdot “G”, may
or may not be present. Some products may
not follow the Generic Marking.
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
rights of others.
98AON27911H
DOCUMENT NUMBER:
DESCRIPTION:
Electronic versions are uncontrolled except when accessed directly from the Document Repository.
Printed versions are uncontrolled except when stamped “CONTROLLED COPY” in red.
PAGE 1 OF 1
SOT23−FL3L
© Semiconductor Components Industries, LLC, 2018 www.onsemi.com
SOT−23
CASE 318BM
ISSUE O
DATE 31 AUG 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
rights of others.
98AON13784G
DOCUMENT NUMBER:
DESCRIPTION:
Electronic versions are uncontrolled except when accessed directly from the Document Repository.
Printed versions are uncontrolled except when stamped “CONTROLLED COPY” in red.
PAGE 1 OF 1
SOT−23
© Semiconductor Components Industries, LLC, 2019 www.onsemi.com
SOT−89 3 LEAD
CASE 528AH
ISSUE O
DATE 31 AUG 2016
2.00 MIN
0.50 45
X
5.30 MIN
1.50
2.23 MIN
0.96 MIN0.90 MIN 2X
3.00 MIN
90
4.50
3.90 C
1.30
0.89
0.54
1.50
0.52
0.30 (2X) C
4.70
4.30 C
1.87
1.45 C
1.40
2.70
2.30 C
3.00
0.30 45
X
123
1
3
0.10 MCAB
A
B
1.70
1.30 C
SEATING PLANE
C
2.70
0.35
0.60
0.40 C
0.50
0.35
2.29
2.13
NOTES: UNLESS OTHERWISE SPECIFIED.
A. REFERENCE TO JEDEC TO-243 VARIATION AA.
B. ALL DIMENSIONS ARE IN MILLIMETERS.
CDOES NOT COMPLY JEDEC STANDARD VALUE.
D. DIMENSIONS ARE EXCLUSIVE OF BURRS,
MOLD FLASH AND TIE BAR PROTRUSION.
E. DIMENSION AND TOLERANCE AS PER ASME
Y14.5−1994.
LAND PATTERN
RECOMMENDATION
C
LSYMM
13
2
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
rights of others.
98AON13791G
DOCUMENT NUMBER:
DESCRIPTION:
Electronic versions are uncontrolled except when accessed directly from the Document Repository.
Printed versions are uncontrolled except when stamped “CONTROLLED COPY” in red.
PAGE 1 OF 1
SOT−89 3 LEAD
© Semiconductor Components Industries, LLC, 2019 www.onsemi.com
www.onsemi.com
1
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 owns the rights to a number of patents, trademarks, copyrights, trade secrets, and other intellectual property. A listing of ON Semiconductor’s product/patent
coverage may be accessed at www.onsemi.com/site/pdf/Patent−Marking.pdf. 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.
Buyer is responsible for its products and applications using ON Semiconductor products, including compliance with all laws, regulations and safety requirements or standards,
regardless of any support or applications information provided by ON Semiconductor. “Typical” parameters which may be provided in ON Semiconductor data sheets and/or
specifications can and do vary in different applications and actual performance may vary over time. All operating parameters, including “Typicals” must be validated for each customer
application by customer’s technical experts. ON Semiconductor does not convey any license under its patent rights nor the rights of others. ON Semiconductor products are not
designed, intended, or authorized for use as a critical component in life support systems or any FDA Class 3 medical devices or medical devices with a same or similar classification
in a foreign jurisdiction or any devices intended for implantation in the human body. Should Buyer purchase or use ON Semiconductor products for any such unintended or unauthorized
application, Buyer shall indemnify and hold ON Semiconductor and its officers, employees, subsidiaries, affiliates, and distributors harmless against all claims, costs, damages, and
expenses, and reasonable attorney fees arising out of, directly or indirectly, any claim of personal injury or death associated with such unintended or unauthorized use, even if such
claim alleges that ON Semiconductor was negligent regarding the design or manufacture of the part. ON Semiconductor is an Equal Opportunity/Affirmative Action Employer. This
literature is subject to all applicable copyright laws and is not for resale in any manner.
PUBLICATION ORDERING INFORMATION
TECHNICAL SUPPORT
North American Technical Support:
Voice Mail: 1 800−282−9855 Toll Free USA/Canada
Phone: 011 421 33 790 2910
LITERATURE FULFILLMENT:
Email Requests to: orderlit@onsemi.com
ON Semiconductor Website: www.onsemi.com
Europe, Middle East and Africa Technical Support:
Phone: 00421 33 790 2910
For additional information, please contact your local Sales Representative
◊
