LM431BIM3 Equivalent & Substitute Parts

Part Overview

The LM431BIM3 is a shunt voltage reference IC with adjustable output, manufactured by Texas Instruments. This component operates as a precision voltage reference in power management applications, offering an adjustable output range from 2.495V to 37V with ±1% tolerance. The device is classified as Last Time Buy, indicating discontinued production. Identifying equivalent and substitute parts is necessary to ensure design continuity and maintain supply chain reliability for applications currently using this component.

Key Parameters

Parameter	Value
Reference Type	Shunt
Output Type	Adjustable
Voltage - Output (Min/Fixed)	2.495V
Voltage - Output (Max)	37V
Current - Output	100 mA
Tolerance	±1%
Temperature Coefficient	50ppm/°C Typical
Current - Cathode	1 mA
Operating Temperature	-40°C ~ 85°C (TA)
Package / Case	TO-236-3, SC-59, SOT-23-3
RoHS Status	ROHS3 Compliant
Moisture Sensitivity Level (MSL)	1 (Unlimited)

Substitute Part Grouping Explanation

Substitution eligibility for the LM431BIM3 is determined by the following critical parameters:

Reference Type: Shunt (must match)
Output Type: Adjustable (must match)
Voltage - Output (Min/Fixed): 2.495V (must match)
Package / Case: TO-236-3, SC-59, SOT-23-3 (must match)
Current - Output: 100 mA (must match)
Tolerance: ±1% or better (equal or tighter)
Operating Temperature Range: Must support application requirements
RoHS Status: ROHS3 Compliant (must match)

Substitute parts are grouped into three categories:

Direct Equivalent: Identical part number with different packaging designation (LM431BIM3/NOPB). Parametric Equivalent with identical specifications (LM431BIM3X/NOPB).

Upgrade Substitutes: Texas Instruments TL431 series parts (TL431AQDBZR, TL431AQDBZRG4, TL431AQDBZRQ1, TL431AQDBZT) offering extended operating temperature range (-40°C ~ 125°C) and lower cathode current (700 µA vs. 1 mA). Maximum output voltage is 36V instead of 37V.

Cross-Manufacturer Alternatives: STMicroelectronics TL431AIL3T and Diodes Incorporated AS431HMANTR-G1 provide functionally equivalent performance with different thermal and tolerance characteristics.

Parameter Comparison

Part Number	Manufacturer	Voltage Output (Max)	Tolerance	Cathode Current	Operating Temp	Product Status	Packaging
LM431BIM3	Texas Instruments	37V	±1%	1 mA	-40°C ~ 85°C	Last Time Buy	SOT-23-3
LM431BIM3/NOPB	Texas Instruments	37V	±1%	1 mA	-40°C ~ 85°C	Active	SOT-23-3
LM431BIM3X/NOPB	Texas Instruments	37V	±1%	1 mA	-40°C ~ 85°C	Active	SOT-23-3
TL431AQDBZR	Texas Instruments	36V	±1%	700 µA	-40°C ~ 125°C	Active	SOT-23-3
TL431AQDBZRG4	Texas Instruments	36V	±1%	700 µA	-40°C ~ 125°C	Discontinued at DiGi Electronics	SOT-23-3
TL431AQDBZRQ1	Texas Instruments	36V	±1%	700 µA	-40°C ~ 125°C	Active	SOT-23-3
TL431AQDBZT	Texas Instruments	36V	±1%	700 µA	-40°C ~ 125°C	Active	SOT-23-3
TL431AIL3T	STMicroelectronics	36V	±1%	700 µA	-40°C ~ 105°C	Active	SOT-23-3
AS431HMANTR-G1	Diodes Incorporated	36V	±0.5%	500 µA	-40°C ~ 125°C	Active	SOT-23-3
TL431AFDT,215	Nexperia USA Inc.	36V	±1%	600 µA	-40°C ~ 125°C	Active	SOT-23-3

Engineering Selection Recommendations

For Direct Replacement (No Design Changes Required): Select LM431BIM3/NOPB or LM431BIM3X/NOPB. Both maintain identical electrical specifications and operating temperature range as the original LM431BIM3. These parts are Active status and provide immediate supply continuity.

For Extended Temperature Applications: TL431AQDBZR, TL431AQDBZRQ1, or TL431AQDBZT support operating temperatures to 125°C, compared to 85°C for the LM431BIM3. These parts are suitable for high-temperature environments. Note that maximum output voltage is 36V instead of 37V; verify this does not exceed application requirements.

For Automotive Applications: TL431AQDBZRQ1 and TL431AFDT,215 carry AEC-Q100 qualification, meeting automotive reliability standards. Both support -40°C ~ 125°C operating range.

For Enhanced Tolerance Requirements: AS431HMANTR-G1 offers ±0.5% tolerance versus ±1% for the LM431BIM3, providing tighter voltage reference accuracy. This part also features lower cathode current (500 µA) and extended temperature range (-40°C ~ 125°C).

For Cross-Manufacturer Sourcing: TL431AIL3T (STMicroelectronics) and TL431AFDT,215 (Nexperia) provide alternative supply sources while maintaining functional equivalence. Both are Active status with established supply availability.

Frequently Asked Questions (FAQ)

Q: Can I use TL431AQDBZR as a direct replacement for LM431BIM3? A: Yes, with one design consideration. The TL431AQDBZR maintains the same reference type, output type, minimum voltage, current output, tolerance, and package. The maximum output voltage is 36V versus 37V for the LM431BIM3. If your application requires output above 36V, this substitute is not suitable. For applications operating at or below 36V, the TL431AQDBZR is functionally equivalent.

Q: What is the difference between LM431BIM3 and LM431BIM3/NOPB? A: Both parts are electrically identical. The /NOPB designation indicates the part is supplied in Cut Tape (CT) and Digi-Reel packaging, whereas the base LM431BIM3 does not specify packaging format. The /NOPB variant is currently Active status, making it the preferred choice for new orders.

Q: Why do TL431 parts have lower cathode current than LM431BIM3? A: The TL431 series is a newer design generation with improved power efficiency. Cathode current is 700 µA for TL431 variants versus 1 mA for LM431BIM3. This lower current consumption does not affect functional equivalence; it represents an improvement in the design.

Q: Is AS431HMANTR-G1 compatible with designs using LM431BIM3? A: Yes. The AS431HMANTR-G1 is functionally compatible with identical reference type, output type, minimum voltage, current output, and package. The AS431HMANTR-G1 offers superior tolerance (±0.5% versus ±1%) and extended operating temperature range (-40°C ~ 125°C versus -40°C ~ 85°C). These are improvements that do not create compatibility issues. Note the maximum output voltage is 36V instead of 37V.

Q: Can I use parts with different maximum output voltages interchangeably? A: Only if your circuit design operates below the lower maximum voltage rating. The LM431BIM3 supports 37V maximum output, while most substitutes support 36V maximum. If your application requires output voltage between 36V and 37V, only LM431BIM3, LM431BIM3/NOPB, or LM431BIM3X/NOPB are suitable. For all other applications, 36V maximum output is acceptable.

Q: What does "Last Time Buy" status mean for LM431BIM3? A: Last Time Buy indicates the manufacturer has discontinued production. Existing inventory may be available from distributors, but no new production runs are planned. This status makes identifying active substitute parts essential for long-term design support.

Q: Are all substitute parts RoHS3 compliant? A: Yes. All parts listed in this reference are ROHS3 Compliant, meeting environmental and regulatory requirements for electronic components.

Request Quote (Ships tomorrow)

Part Number

Quantity

Company

Contact Name

E-mail

Message