LM431ACM Equivalent & Substitute Parts

Part Overview

The LM431ACM is a shunt voltage reference IC manufactured by Texas Instruments, designed for adjustable voltage regulation applications. This component provides a fixed output voltage of 2.495V with a maximum output of 37V and supports output currents up to 100 mA. The LM431ACM is classified as obsolete, making equivalent and substitute parts necessary for ongoing design support and production continuity. Shunt voltage reference ICs like the LM431ACM are critical in power management circuits where precise voltage regulation and feedback control are required.

Substiute Parts

LM431ACM

Texas InstrumentsIn Stock: 110678LM431ACM Datasheet

Current PartRFQ

LM431ACM/NOPB

National SemiconductorIn Stock: 1994LM431ACM/NOPB Datasheet

DirectRFQ

TL431ACD

STMicroelectronicsIn Stock: 5832TL431ACD Datasheet

MFR RecommendedRFQ

TL431ACDR

Texas InstrumentsIn Stock: 55199TL431ACDR Datasheet

MFR RecommendedRFQ

TL431ACDRG4

Texas InstrumentsIn Stock: 3411TL431ACDRG4 Datasheet

MFR RecommendedRFQ

TL431ACDT

STMicroelectronicsIn Stock: 22261TL431ACDT Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the LM431ACM is determined by strict alignment of the following electrical and mechanical parameters:

Critical Substitution Parameters:

• Reference Type: Shunt
• Output Type: Adjustable
• Package / Case: 8-SOIC (0.154", 3.90mm Width)
• Mounting Type: Surface Mount
• Operating Temperature Range: 0°C ~ 70°C (TA)
• Output Voltage Range: Minimum 2.495V, Maximum ≥36V
• Output Current: 100 mA
• Cathode Current: ≤1 mA

Substitute parts are grouped into two categories based on product status and compliance:

Category 1: Direct Equivalent (Active Status)

• LM431ACM/NOPB (National Semiconductor) - Active status, identical electrical specifications
• TL431ACDR (Texas Instruments) - Active status, improved tolerance (±1%), compatible voltage range (36V max)
• TL431ACDT (STMicroelectronics) - Active status, improved tolerance (±1%), compatible voltage range (36V max)

Category 2: Functional Equivalent (Obsolete Status)

• TL431ACD (STMicroelectronics) - Obsolete status, improved tolerance (±1%), compatible voltage range (36V max)
• TL431ACDRG4 (Texas Instruments) - Obsolete status, improved tolerance (±1%), compatible voltage range (36V max)

All substitute parts maintain the 8-SOIC package, surface mount configuration, and operating temperature range of the original LM431ACM.

Parameter Comparison

Engineering Selection Recommendations

For Active Production (Recommended): Select TL431ACDR (Texas Instruments) or TL431ACDT (STMicroelectronics) as primary substitutes. Both parts are in active production status, ensuring long-term availability and supply chain stability. TL431ACDR offers the advantage of higher inventory levels (55,100 pcs) and Cut Tape & Digi-Reel packaging options. Both parts provide improved tolerance specifications (±1% versus ±2.2%) and ROHS3 compliance, supporting modern environmental and regulatory requirements.

For Legacy System Support: LM431ACM/NOPB (National Semiconductor) maintains identical electrical specifications to the original LM431ACM, including the ±2.2% tolerance and 1 mA cathode current. This part is suitable for applications requiring exact parameter matching and is currently in active production status with 1,900 pcs available inventory.

Voltage Range Consideration: The LM431ACM supports a maximum output voltage of 37V, while all substitute parts (TL431 series) support 36V maximum. This 1V difference is acceptable for most applications operating below 36V. Applications requiring operation above 36V should retain the original LM431ACM or source alternative reference designs.

Compliance and Certification: All substitute parts carry ROHS3 compliance and unlimited MSL ratings, supporting deployment in modern manufacturing environments. The original LM431ACM is RoHS non-compliant; migration to compliant substitutes is recommended for new designs and long-term production continuity.

Frequently Asked Questions (FAQ)

Q: Can TL431ACDR be used as a direct replacement for LM431ACM? A: Yes. Both parts share identical package (8-SOIC), mounting type (surface mount), operating temperature range (0°C ~ 70°C), output voltage minimum (2.495V), and output current (100 mA). The TL431ACDR provides improved tolerance (±1% versus ±2.2%) and is in active production status. The maximum output voltage differs by 1V (36V versus 37V), which is acceptable for most applications.

Q: What is the difference between LM431ACM/NOPB and TL431ACDR? A: LM431ACM/NOPB maintains the original ±2.2% tolerance and 1 mA cathode current specification. TL431ACDR improves tolerance to ±1% and reduces cathode current to 600 µA. Both are electrically compatible and use the same 8-SOIC package. LM431ACM/NOPB is preferred for applications requiring exact parameter matching; TL431ACDR is preferred for new designs and active production environments.

Q: Are all substitute parts available in the same package? A: Yes. All substitute parts use the 8-SOIC (0.154", 3.90mm Width) package with surface mount configuration, ensuring PCB layout compatibility with the original LM431ACM.

Q: Which substitute part has the best availability? A: TL431ACDR (Texas Instruments) has the highest inventory level at 55,100 pcs, followed by TL431ACDT (STMicroelectronics) at 22,200 pcs. Both parts are in active production status, supporting long-term supply chain reliability.

Q: Do substitute parts support the same operating temperature range? A: Yes. All substitute parts operate across the 0°C ~ 70°C (TA) temperature range, matching the original LM431ACM specification.

Q: What is the significance of the cathode current difference (1 mA versus 600 µA)? A: The cathode current specification defines the minimum current required to maintain regulation. The TL431 series parts require 600 µA minimum cathode current, compared to 1 mA for the LM431ACM. This lower requirement in substitute parts reduces power dissipation and provides design flexibility in current-limited applications.

Q: Are substitute parts RoHS compliant? A: Yes. All substitute parts (TL431 series) are ROHS3 compliant. The original LM431ACM is RoHS non-compliant. Migration to compliant substitutes is recommended for new designs and regulatory compliance.