LM431BCZXA Replacement: TL431CLPRAG, TL431ILPRPG

Original Part

LM431BCZXA

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Shunt Voltage Reference IC Adjustable 2.495V 36 VV ±1% 100 mA TO-92-3

Alternative Part

TL431CLPRAG

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Shunt Voltage Reference IC Adjustable 2.495V 36 VV ±2.2% 100 mA TO-92 (TO-226)

TL431ILPRPG

onsemi

Shunt Voltage Reference IC Adjustable 2.495V 36 VV ±2.2% 100 mA TO-92-3

1. TL431CLPRAG Substitution Conclusion From a core functionality perspective, the TL431CLPRAG can serve as a direct replacement for the original LM431BCZXA, as both are 2.495V reference, 36V, 100mA adjustable shunt regulators with pin-to-pin compatibility and identical temperature coefficients. The key deviation lies in the initial accuracy (tolerance), which is relaxed from ±1% to ±2.2%. A direct drop-in replacement without screening or calibration will result in the initial reference voltage deviation range more than doubling. This may impact applications with stringent absolute voltage accuracy requirements, such as high-precision measurement or ADC/DAC references. Furthermore, its package is specified as "TO-92-3 Long Body," which might introduce subtle physical dimension differences compared to the standard TO-92-3 package of the original part. Verification of the installation footprint is recommended.

2. TL431ILPRPG Substitution Conclusion The TL431ILPRPG is a functionally and electrically compatible drop-in replacement for the LM431BCZXA, sharing identical pinout and core electrical parameters. Similarly, the primary difference is the looser initial accuracy, degraded from ±1% to ±2.2%. This directly translates to reduced initial precision of the circuit's reference voltage; designs sensitive to accuracy must evaluate the acceptability of this increased deviation. The package (TO-226AA) is identical to the original, posing no physical compatibility risk. Compared to the original part, the "I" prefix typically denotes an industrial-grade temperature range. The datasheet does not explicitly specify the temperature grade of the original LM431BCZXA. If the original design was for commercial-grade applications, this difference is inconsequential. However, for operation in wider temperature environments, the TL431ILPRPG may offer an advantage.

Analysis ID: 54F4-256B000

Based on part parameters and for reference only. Not to be used for procurement or production.