LM431ACZ/LFT3 Equivalent & Substitute Parts

Part Overview

The LM431ACZ/LFT3 is an adjustable shunt voltage reference IC manufactured by Texas Instruments, designed for precision voltage regulation and reference applications. This through-hole TO-92-3 packaged component delivers a fixed output voltage of 2.495V with adjustable capability up to 37V, supporting 100mA output current. The device is currently in active production status and ROHS3 compliant. Substitute parts are identified when equivalent electrical performance is required but alternative packaging, mounting technology, or supplier sourcing is necessary.

Substiute Parts

LM431ACZ/LFT3

Texas InstrumentsIn Stock: 6364LM431ACZ/LFT3 Datasheet

Current PartRFQ

TL431FDT,215

Nexperia USA Inc.In Stock: 7858TL431FDT,215 Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the LM431ACZ/LFT3 is determined by the following core electrical and mechanical parameters:

• Reference Type: Shunt (must match)
• Output Type: Adjustable (must match)
• Voltage - Output (Min/Fixed): 2.495V (must match)
• Voltage - Output (Max): 36V or higher (must be ≥36V)
• Current - Output: 100mA (must match)
• Current - Cathode: 1mA (must match)
• Tolerance: ±2% or better (must be ≤±2.2%)
• Product Status: Active (must be active)
• RoHS Status: ROHS3 Compliant (must match)

The identified substitute TL431FDT,215 meets all substitution criteria. Differences in mounting type (surface mount vs. through hole), package form factor (TO-236AB vs. TO-92-3), and operating temperature range do not affect electrical equivalence but require circuit board redesign and layout modification.

Parameter Comparison

Engineering Selection Recommendations

The TL431FDT,215 is electrically equivalent to the LM431ACZ/LFT3 for shunt voltage reference applications. Both devices maintain active product status and ROHS3 compliance. The substitute offers improved tolerance specification (±2% vs. ±2.2%) and extended operating temperature range (-40°C ~ 125°C vs. 0°C ~ 70°C), with additional automotive-grade qualification (AEC-Q100).

Selection between these parts depends on application requirements:

• Use LM431ACZ/LFT3 when through-hole TO-92-3 packaging is required for existing PCB designs or manual assembly processes.
• Use TL431FDT,215 when surface-mount TO-236AB packaging is required for automated assembly, when automotive qualification is necessary, or when extended temperature operation is specified.

Both parts are suitable for precision voltage reference circuits, power supply feedback networks, and adjustable regulator applications within their respective operating temperature ranges.

Frequently Asked Questions (FAQ)

Q: Can TL431FDT,215 directly replace LM431ACZ/LFT3 in an existing circuit?

A: Electrical substitution is valid. The TL431FDT,215 provides identical voltage reference output (2.495V adjustable to 36V), matching current ratings (100mA output, 1mA cathode), and equivalent tolerance (±2%). However, physical substitution requires PCB redesign because the devices use different mounting technologies (through-hole vs. surface-mount) and package form factors (TO-92-3 vs. TO-236AB/SOT-23-3).

Q: What are the key parameters that determine substitution eligibility?

A: Substitution is valid when the following parameters match or exceed the original specification: Reference Type (Shunt), Output Type (Adjustable), Output Voltage (2.495V minimum, 36V or higher maximum), Output Current (100mA), Cathode Current (1mA), Tolerance (±2.2% or better), Product Status (Active), and RoHS Compliance (ROHS3). Temperature coefficient and operating temperature range are secondary considerations unless the application specifies extreme temperature operation.

Q: Does the TL431FDT,215 automotive qualification affect its use in non-automotive applications?

A: No. Automotive-grade qualification (AEC-Q100) indicates enhanced reliability testing and stricter manufacturing controls. These devices are fully suitable for industrial, consumer, and commercial applications. The automotive qualification does not restrict use in other markets.

Q: What is the impact of the 1V difference in maximum output voltage (37V vs. 36V)?

A: For most applications, this difference is negligible. The 1V reduction (from 37V to 36V maximum) does not affect circuit functionality in standard voltage reference applications. Verify application requirements if designs operate near the maximum voltage specification.

Q: Are there pin-compatible alternatives listed for the TL431FDT,215?

A: Yes. The TL431FDT,215 datasheet references additional substitutes including KA431SLMFTF, NCP432BCSNT1G, TL432BQDBZRQ1, TL432AIDBZRG4, and TL431IDBZT. These alternatives maintain the same functional specifications and pin configuration but may differ in packaging, temperature range, or manufacturer.