LM431CIMX Equivalent & Substitute Parts

Part Overview

The LM431CIMX is a shunt voltage reference IC manufactured by Texas Instruments, classified as a Power Management (PMIC) component. This adjustable reference provides a 2.5V output with ±0.6%/+0.4% tolerance and supports output currents up to 100 mA in an 8-SOIC surface mount package. The part is currently listed as obsolete, making equivalent and substitute parts necessary for ongoing design support and procurement.

Substiute Parts

LM431CIMX

Texas InstrumentsIn Stock: 1867LM431CIMX Datasheet

Current PartRFQ

TL431BID

onsemiIn Stock: 3433TL431BID Datasheet

DirectRFQ

TL431BIDR

Texas InstrumentsIn Stock: 55248TL431BIDR Datasheet

DirectRFQ

TL431AID

STMicroelectronicsIn Stock: 233276TL431AID Datasheet

MFR RecommendedRFQ

TL431AIDR

Texas InstrumentsIn Stock: 45158TL431AIDR Datasheet

MFR RecommendedRFQ

LM431CIMX

onsemiIn Stock: 1892LM431CIMX Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the LM431CIMX is determined by the following critical parameters:

• Package compatibility: 8-SOIC (0.154", 3.90mm Width) surface mount only
• Reference type: Shunt voltage reference
• Output type: Adjustable
• Output voltage range: Minimum 2.495V to 2.5V, maximum 36V to 37V
• Output current: 100 mA
• Operating temperature range: -40°C to 85°C or wider
• Tolerance specification: ±0.4% to ±1% acceptable
• Cathode current: 700 µA to 1 mA acceptable

All substitute parts listed maintain these core electrical and mechanical parameters within acceptable engineering tolerances for direct circuit substitution.

Parameter Comparison

Engineering Selection Recommendations

Primary Recommendation: TL431AIDR (Texas Instruments)

The TL431AIDR is the preferred substitute for the LM431CIMX. Both parts are manufactured by Texas Instruments, share identical 8-SOIC packaging, and maintain full electrical compatibility. The TL431AIDR is currently in active production status, ensuring long-term availability. It carries ROHS3 compliance and meets all operating temperature and current specifications. The ±1% tolerance is acceptable for applications originally designed with the LM431CIMX's -0.6%/+0.4% specification.

Secondary Recommendation: LM431CIMX (onsemi)

The onsemi-manufactured LM431CIMX provides an alternative with identical part numbering. This variant maintains ROHS3 compliance, active product status, and matches the original temperature coefficient specification of 50ppm/°C. Output voltage and current ratings are equivalent within acceptable tolerances.

Alternative Option: TL431BIDR (Texas Instruments)

The TL431BIDR offers tighter tolerance (±0.5%) compared to the TL431AIDR and maintains active production status with ROHS3 compliance. This part is suitable for applications requiring improved voltage accuracy. Cathode current is specified at 700 µA versus the original 1 mA specification.

Not Recommended: TL431BID (onsemi)

While electrically compatible, the TL431BID carries RoHS non-compliance status and obsolete product status, making it unsuitable for new designs or long-term procurement strategies.

Frequently Asked Questions (FAQ)

Q: Can I substitute the LM431CIMX with any TL431 variant?

A: No. Substitution is limited to parts maintaining the 8-SOIC package, 100 mA output current, adjustable reference type, and operating temperature range of -40°C to 85°C or wider. Tolerance specifications must be ±1% or tighter. The TL431AIDR, TL431BIDR, and TL431AID meet these criteria.

Q: What is the difference between the TL431AIDR and TL431BIDR?

A: Both parts are manufactured by Texas Instruments in 8-SOIC packaging with identical electrical ratings. The primary difference is tolerance specification: TL431AIDR offers ±1% tolerance, while TL431BIDR provides ±0.5% tolerance. The TL431BIDR is suitable for applications requiring tighter voltage accuracy.

Q: Is the onsemi LM431CIMX equivalent to the Texas Instruments LM431CIMX?

A: Yes. Both variants share identical part numbering and electrical specifications, including 2.495V minimum output voltage, 36V maximum output voltage, 100 mA output current, and ±0.5% tolerance. Both are ROHS3 compliant and in active production status.

Q: Why is RoHS compliance important for this substitution?

A: RoHS3 compliance ensures the part meets environmental and regulatory standards for lead-free manufacturing. The original LM431CIMX is ROHS3 compliant. Substitute parts should maintain this compliance status for consistency with design standards and regulatory requirements.

Q: Can I use the TL431BID as a substitute?

A: The TL431BID is electrically compatible but carries RoHS non-compliance and obsolete product status. It is not recommended for new designs or long-term applications due to regulatory and availability concerns.

Q: What is the significance of cathode current differences (700 µA vs. 1 mA)?

A: Cathode current represents the minimum operating current required for proper device operation. The original LM431CIMX specifies 1 mA, while TL431AIDR and TL431BIDR specify 700 µA. The lower specification of substitute parts provides greater design flexibility and reduced power consumption in low-current applications.

Q: Are there temperature range differences between substitutes?

A: The TL431AID (STMicroelectronics) operates across -40°C to 105°C, providing an extended upper temperature limit compared to the original -40°C to 85°C specification. Other substitutes maintain the original -40°C to 85°C range. Extended temperature range may be beneficial for high-temperature applications.