LM431BCM/NOPB Equivalent & Substitute Parts

Part Overview

The LM431BCM/NOPB is a shunt voltage reference IC manufactured by Texas Instruments, classified as a Power Management (PMIC) component. This adjustable reference operates at 2.495V output with a maximum voltage rating of 37V, delivering 100 mA output current with ±1% tolerance. The device is housed in an 8-SOIC surface mount package and maintains active product status with full RoHS3 compliance.

Substitute parts are necessary when the primary part becomes unavailable, when alternative packaging formats are required, or when design flexibility demands components from different manufacturers while maintaining electrical and mechanical compatibility.

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	0°C ~ 70°C (TA)
Package / Case	8-SOIC (0.154", 3.90mm Width)
Mounting Type	Surface Mount
RoHS Status	ROHS3 Compliant

Substitute Part Grouping Explanation

Substitution eligibility is determined by strict alignment with the following electrical and mechanical parameters:

Critical Matching Parameters:

Reference Type: Shunt (all substitutes must be shunt references)
Output Type: Adjustable (all substitutes must support adjustable output)
Voltage - Output (Min/Fixed): 2.495V (all substitutes must match this minimum)
Current - Output: 100 mA (all substitutes must support this current rating)
Package / Case: 8-SOIC (0.154", 3.90mm Width) (all substitutes must use identical package)
Mounting Type: Surface Mount (all substitutes must be surface mount)

Flexible Parameters (allowing substitution with documented differences):

Voltage - Output (Max): 36V or 37V (both acceptable for applications not requiring the full 37V range)
Tolerance: ±1% or ±2.2% (tolerance variance acceptable based on circuit requirements)
Current - Cathode: 600 µA or 1 mA (both acceptable for shunt reference operation)
Temperature Coefficient: 50ppm/°C or unspecified (both acceptable for standard applications)
Operating Temperature: 0°C ~ 70°C or -25°C ~ 85°C (extended range acceptable)
Product Status: Active or Obsolete (both available for procurement)

Substitutes are grouped by tolerance specification (±1% precision grade vs. ±2.2% standard grade) and by manufacturer to facilitate selection based on availability and supply chain requirements.

Parameter Comparison

Part Number	Manufacturer	Voltage Output (Min)	Voltage Output (Max)	Current Output	Tolerance	Current Cathode	Operating Temp	Product Status	Inventory
LM431BCM/NOPB	Texas Instruments	2.495V	37V	100 mA	±1%	1 mA	0°C ~ 70°C	Active	2,100 Pcs
LM431BCMX/NOPB	National Semiconductor	2.495V	37V	100 mA	±1%	1 mA	0°C ~ 70°C	Active	17,378 Pcs
TL431ACDR	Texas Instruments	2.495V	36V	100 mA	±1%	600 µA	0°C ~ 70°C	Active	55,100 Pcs
TL431ACDRG4	Texas Instruments	2.495V	36V	100 mA	±1%	600 µA	0°C ~ 70°C	Obsolete	3,400 Pcs
TL431ACDG	onsemi	2.495V	36V	100 mA	±1%	1 mA	0°C ~ 70°C	Active	3,250 Pcs
TL431ACDR2G	onsemi	2.495V	36V	100 mA	±1%	1 mA	0°C ~ 70°C	Active	10,200 Pcs
TL431ACD	STMicroelectronics	2.495V	36V	100 mA	±1%	600 µA	0°C ~ 70°C	Obsolete	5,800 Pcs
TL431ACDT	STMicroelectronics	2.495V	36V	100 mA	±1%	600 µA	0°C ~ 70°C	Active	22,200 Pcs
TL431CDR	Texas Instruments	2.495V	36V	100 mA	±2.2%	1 mA	0°C ~ 70°C	Active	105,300 Pcs
TL431CD	Fairchild Semiconductor	2.495V	36V	100 mA	±2.21%	1 mA	-25°C ~ 85°C	Obsolete	33,044 Pcs
TL431CDT	STMicroelectronics	2.495V	36V	100 mA	±2.21%	1 mA	0°C ~ 70°C	Active	2,515 Pcs

Engineering Selection Recommendations

Primary Substitutes (±1% Tolerance, Active Status):

LM431BCMX/NOPB and TL431ACDR are the preferred substitutes. LM431BCMX/NOPB maintains identical electrical specifications including 37V maximum output voltage and 1 mA cathode current, with significantly higher inventory availability (17,378 Pcs). TL431ACDR offers the highest inventory level (55,100 Pcs) with active product status and full RoHS3 compliance, though maximum output voltage is rated at 36V instead of 37V.

Secondary Substitutes (±1% Tolerance, Active Status):

TL431ACDT (STMicroelectronics, 22,200 Pcs) and TL431ACDR2G (onsemi, 10,200 Pcs) provide additional sourcing options with ±1% tolerance and active product status. TL431ACDG (onsemi, 3,250 Pcs) is available but with lower inventory levels.

Standard Tolerance Alternatives (±2.2% Tolerance, Active Status):

TL431CDR (Texas Instruments, 105,300 Pcs) and TL431CDT (STMicroelectronics, 2,515 Pcs) are suitable for applications where ±2.2% tolerance is acceptable. TL431CDR offers the highest inventory availability across all substitutes.

Obsolete Parts (Not Recommended for New Designs):

TL431ACDRG4, TL431ACD, and TL431CD are obsolete and should not be selected for new designs despite available inventory.

All recommended substitutes maintain 8-SOIC surface mount packaging, 100 mA output current, and RoHS3 compliance. Selection should prioritize active product status and inventory availability for supply chain reliability.

Frequently Asked Questions (FAQ)

Q: Can TL431ACDR be used as a direct replacement for LM431BCM/NOPB?

A: TL431ACDR is electrically compatible for most applications. Both devices are shunt voltage references with adjustable output, 2.495V minimum output, 100 mA current rating, ±1% tolerance, and identical 8-SOIC packaging. The primary difference is maximum output voltage: TL431ACDR is rated to 36V while LM431BCM/NOPB is rated to 37V. For circuits operating below 36V, substitution is direct. For circuits requiring the full 37V range, LM431BCMX/NOPB is the appropriate substitute.

Q: What is the difference between ±1% and ±2.2% tolerance parts?

A: Tolerance specifies the accuracy of the output voltage reference. ±1% tolerance (LM431BCM/NOPB, TL431ACDR, TL431ACDT) provides tighter voltage regulation suitable for precision analog circuits. ±2.2% tolerance (TL431CDR, TL431CDT) is acceptable for applications with less stringent voltage accuracy requirements. Selection depends on circuit design specifications.

Q: Are there packaging differences between substitutes?

A: All listed substitutes use 8-SOIC (0.154", 3.90mm Width) surface mount packaging. Packaging variants (Tube, Cut Tape & Digi-Reel, Tape & Reel) refer to shipping and handling formats only and do not affect electrical performance or PCB compatibility.

Q: Why do some parts have different cathode current specifications?

A: Cathode current (1 mA vs. 600 µA) represents the minimum operating current for the shunt reference. Both values are acceptable for standard shunt reference operation. Lower cathode current (600 µA) may provide marginal power consumption benefits in battery-powered applications, but this difference is not significant for most designs.

Q: Can I use TL431CDR (±2.2% tolerance) instead of LM431BCM/NOPB (±1% tolerance)?

A: Substitution is possible only if circuit design tolerates ±2.2% voltage accuracy. If the original design requires ±1% precision, TL431CDR is not suitable. Verify circuit specifications before selecting a standard tolerance part.

Q: What is the significance of "Active" vs. "Obsolete" product status?

A: Active products are currently manufactured and supported by the supplier, ensuring long-term availability and supply chain reliability. Obsolete products are no longer manufactured and should not be selected for new designs. Existing inventory of obsolete parts may be available but represents a finite supply.

Q: Is LM431BCMX/NOPB identical to LM431BCM/NOPB?

A: LM431BCMX/NOPB and LM431BCM/NOPB are functionally equivalent with identical electrical specifications. Both are manufactured by National Semiconductor (now part of Texas Instruments), maintain ±1% tolerance, 37V maximum output, and active product status. The "X" designation indicates a specific manufacturing variant. Both are direct substitutes for each other.

Request Quote (Ships tomorrow)

Part Number

Quantity

Company

Contact Name

E-mail

Message