LM431ACM3 Equivalent & Substitute Parts

Part Overview

The LM431ACM3 is a shunt voltage reference IC with adjustable output, manufactured by Texas Instruments. This component is classified as obsolete, which necessitates identification of equivalent and substitute parts for ongoing design requirements and production continuity. The LM431ACM3 operates as an adjustable shunt regulator suitable for precision voltage reference applications in power management circuits.

Substiute Parts

LM431ACM3

Texas InstrumentsIn Stock: 3693LM431ACM3 Datasheet

Current PartRFQ

LM431ACM3/NOPB

Texas InstrumentsIn Stock: 8835LM431ACM3/NOPB Datasheet

DirectRFQ

LM431ACM3X/NOPB

Texas InstrumentsIn Stock: 26330LM431ACM3X/NOPB Datasheet

Parametric EquivalentRFQ

AS431HMBNTR-G1

Diodes IncorporatedIn Stock: 4050AS431HMBNTR-G1 Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the LM431ACM3 is determined by the following critical parameters:

Electrical Compatibility Requirements:

• Reference Type: Shunt
• Output Type: Adjustable
• Voltage - Output (Min/Fixed): 2.495V
• Voltage - Output (Max): 37 V or greater
• Current - Output: 100 mA
• Package / Case: TO-236-3, SC-59, SOT-23-3 (SOT-23-3)
• Mounting Type: Surface Mount

Substitute Categories:

1. Direct Manufacturer Equivalent (LM431ACM3/NOPB): Identical electrical specifications and packaging. Differs only in product status (Active vs. Obsolete) and RoHS compliance level.

2. Parametric Equivalent (LM431ACM3X/NOPB): Identical electrical specifications and packaging. Represents an alternative variant within the same product line with Active status.

3. MFR Recommended Substitute (AS431HMBNTR-G1): Meets core electrical requirements with enhanced performance characteristics (±1% tolerance vs. ±2.2%, 20ppm/°C vs. 50ppm/°C). Voltage - Output (Max) is 36 V, which is within acceptable range for most applications. Extended operating temperature range (-40°C ~ 125°C vs. 0°C ~ 70°C).

Parameter Comparison

Engineering Selection Recommendations

For Direct Replacement (Pin-Compatible, Electrical Equivalent):

LM431ACM3/NOPB and LM431ACM3X/NOPB are recommended as primary substitutes. Both parts maintain identical electrical specifications and packaging. LM431ACM3/NOPB and LM431ACM3X/NOPB carry Active product status and ROHS3 compliance, addressing the obsolescence of the original LM431ACM3. Selection between these two variants depends on availability and supply chain requirements.

For Enhanced Performance Applications:

AS431HMBNTR-G1 (Diodes Incorporated) is suitable when improved accuracy and extended temperature range are beneficial. This part offers ±1% tolerance versus ±2.2%, and 20ppm/°C temperature coefficient versus 50ppm/°C. The maximum output voltage is 36 V, which is acceptable for applications not requiring the full 37 V specification. The extended operating temperature range (-40°C ~ 125°C) supports broader environmental conditions. Lower cathode current (500 µA vs. 1 mA) may reduce power consumption in certain circuit topologies.

Compliance Considerations:

All substitute parts are ROHS3 compliant and REACH unaffected, meeting modern regulatory requirements. The original LM431ACM3 is RoHS non-compliant, making transition to compliant alternatives necessary for new designs and production continuity.

Frequently Asked Questions (FAQ)

Q: Can LM431ACM3/NOPB be used as a direct replacement for LM431ACM3?

A: Yes. LM431ACM3/NOPB is electrically and mechanically identical to LM431ACM3. The primary differences are product status (Active vs. Obsolete) and RoHS compliance level. Pin configuration, electrical performance, and SOT-23-3 packaging are identical.

Q: What is the difference between LM431ACM3/NOPB and LM431ACM3X/NOPB?

A: Both parts are Texas Instruments LM431 variants with identical electrical specifications and packaging. The difference is a product line variant designation. Selection depends on availability and supply chain sourcing.

Q: Is AS431HMBNTR-G1 a suitable replacement if my application requires 37 V maximum output?

A: AS431HMBNTR-G1 has a maximum output voltage of 36 V. For applications requiring the full 37 V specification, LM431ACM3/NOPB or LM431ACM3X/NOPB are recommended. For applications operating below 36 V, AS431HMBNTR-G1 is compatible.

Q: What are the advantages of AS431HMBNTR-G1 over the LM431 variants?

A: AS431HMBNTR-G1 offers improved tolerance (±1% vs. ±2.2%), lower temperature coefficient (20ppm/°C vs. 50ppm/°C), and extended operating temperature range (-40°C ~ 125°C vs. 0°C ~ 70°C). These characteristics provide better accuracy and stability across wider environmental conditions.

Q: Are all substitute parts available in the same packaging?

A: Yes. All substitute parts use SOT-23-3 packaging (TO-236-3, SC-59). Pin configuration and footprint are identical, enabling direct PCB-level substitution without layout modifications.

Q: What is the impact of lower cathode current in AS431HMBNTR-G1?

A: AS431HMBNTR-G1 has cathode current of 500 µA versus 1 mA in LM431 variants. This lower current may reduce power dissipation in applications where cathode current contributes significantly to total circuit power consumption. Circuit design must accommodate this parameter difference.

Q: Are all substitute parts RoHS compliant?

A: Yes. LM431ACM3/NOPB, LM431ACM3X/NOPB, and AS431HMBNTR-G1 are all ROHS3 compliant. The original LM431ACM3 is RoHS non-compliant, making compliant substitutes necessary for regulatory adherence.