LM431BCZ/NOPB Equivalent & Substitute Parts

Part Overview

The LM431BCZ/NOPB is a shunt voltage reference IC manufactured by Texas Instruments, designed for adjustable voltage regulation applications. This through-hole component operates across a 2.495V to 37V output range with ±1% tolerance and 100 mA output current capability. The part is currently in active production status with 2401 units in stock.

Substitute parts are necessary when the LM431BCZ/NOPB reaches end-of-life, when alternative manufacturers offer improved specifications, or when design requirements demand enhanced performance characteristics such as tighter tolerance, extended temperature range, or lower temperature coefficient.

Substiute Parts

LM431BCZ/NOPB

Texas InstrumentsIn Stock: 2451LM431BCZ/NOPB Datasheet

Current PartRFQ

TL431ACLP

onsemiIn Stock: 125204TL431ACLP Datasheet

DirectRFQ

AS431AZTR-E1

Diodes IncorporatedIn Stock: 117279AS431AZTR-E1 Datasheet

MFR RecommendedRFQ

AS431AZTR-G1

Diodes IncorporatedIn Stock: 150275AS431AZTR-G1 Datasheet

MFR RecommendedRFQ

AS431BZTR-G1

Diodes IncorporatedIn Stock: 314459AS431BZTR-G1 Datasheet

MFR RecommendedRFQ

AS431IAZTR-G1

Diodes IncorporatedIn Stock: 56453AS431IAZTR-G1 Datasheet

MFR RecommendedRFQ

TL431AFDT,215

Nexperia USA Inc.In Stock: 59193TL431AFDT,215 Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the LM431BCZ/NOPB is determined by the following critical parameters:

• Reference Type: Shunt (all substitutes must be shunt-type references)
• Output Type: Adjustable (all substitutes must support adjustable output)
• Output Voltage Range: Minimum 2.495V to 2.5V; Maximum 36V to 37V
• Output Current: 100 mA (all substitutes must support this current level)
• Tolerance: ±1% or better (±0.5% is acceptable as tighter tolerance)
• Mounting Type: Through Hole (package form factor compatibility)
• Package: TO-92-3 or equivalent TO-226-3 footprint

The substitute parts identified below meet these core electrical and mechanical requirements. Variations in temperature coefficient, operating temperature range, and cathode current represent performance enhancements or design flexibility rather than incompatibility factors.

Parameter Comparison

Engineering Selection Recommendations

Through-Hole TO-92-3 Package Substitutes (Direct Footprint Compatible):

The following parts maintain identical through-hole TO-92-3 package compatibility with the LM431BCZ/NOPB:

• AS431AZTR-E1, AS431AZTR-G1, AS431BZTR-G1, AS431IAZTR-G1 (Diodes Incorporated): All active production status. These parts offer extended operating temperature range (-40°C to 125°C) compared to the original specification (0°C to 70°C). AS431AZTR-E1 and AS431IAZTR-G1 provide ±0.5% tolerance with improved temperature coefficient (20ppm/°C). AS431BZTR-G1 maintains ±1% tolerance. All are ROHS3 compliant.

• TL431ACLP (onsemi): Obsolete product status. While electrically compatible, this part is no longer in active production and should not be selected for new designs.

Surface-Mount SOT-23-3 Package Substitute (Footprint Change Required):

• TL431AFDT,215 (Nexperia USA Inc.): Active production status with automotive-grade qualification (AEC-Q100). This part requires PCB redesign due to surface-mount TO-236-3 (SOT-23-3) package format. It is ROHS3 compliant and operates across -40°C to 125°C.

Recommendation Priority:

For direct replacement without PCB modification, select from the Diodes Incorporated AS431 series (AZTR-E1, AZTR-G1, BZTR-G1, or IAZTR-G1). All maintain active production status and ROHS3 compliance. Avoid TL431ACLP due to obsolete status.

Frequently Asked Questions (FAQ)

Q: Can AS431AZTR-E1 or AS431IAZTR-G1 replace LM431BCZ/NOPB in existing designs?

A: Yes. Both parts are electrically compatible shunt voltage references with identical TO-92-3 through-hole packages. They support the same 100 mA output current and adjustable output voltage range. The ±0.5% tolerance and 20ppm/°C temperature coefficient represent performance improvements over the original ±1% tolerance and 50ppm/°C specification.

Q: What is the difference between AS431AZTR-G1 and AS431BZTR-G1?

A: Both parts are manufactured by Diodes Incorporated with identical TO-92-3 packages and operating temperature range (-40°C to 125°C). The primary difference is tolerance: AS431AZTR-G1 specifies ±0.5% tolerance, while AS431BZTR-G1 specifies ±1% tolerance. Both support 100 mA output current and are ROHS3 compliant.

Q: Why is TL431ACLP listed as obsolete?

A: TL431ACLP is marked as obsolete product status by onsemi. While it meets the electrical specifications for substitution, new designs should not incorporate obsolete components. Active alternatives from Diodes Incorporated (AS431 series) are recommended.

Q: Can TL431AFDT,215 be used as a direct replacement?

A: TL431AFDT,215 is electrically compatible but requires PCB redesign. It uses a surface-mount TO-236-3 (SOT-23-3) package instead of the through-hole TO-92-3 package of the LM431BCZ/NOPB. This part is automotive-grade qualified (AEC-Q100) and suitable for applications requiring extended temperature operation (-40°C to 125°C).

Q: What is the maximum output voltage difference between LM431BCZ/NOPB and substitute parts?

A: The LM431BCZ/NOPB specifies 37V maximum output, while most substitute parts (TL431ACLP, AS431 series, TL431AFDT,215) specify 36V maximum output. This 1V difference is acceptable for most applications but must be verified against circuit design requirements.

Q: Are all substitute parts ROHS3 compliant?

A: All active production substitutes (AS431AZTR-E1, AS431AZTR-G1, AS431BZTR-G1, AS431IAZTR-G1, TL431AFDT,215) are ROHS3 compliant. TL431ACLP compliance status is not specified in the provided data.