LM431BCZX Replacement: NCP431AVLPRAG, TL431CLPRPG

Original Part

LM431BCZX

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

Alternative Part

NCP431AVLPRAG

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Shunt Voltage Reference IC Adjustable 2.5V 36 VV ±1% 40 µA TO-92 (TO-226)

TL431CLPRPG

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

1. NCP431AVLPRAG Substitution Conclusion The NCP431AVLPRAG aligns with the LM431BCZX in core parameters such as voltage range, temperature drift, and tolerance (±1%). However, a critical deviation is its output current capability of only 40 µA, which is significantly lower than the original’s 100 mA, while its cathode operating current requirement is 100 mA (compared to 1 mA for the original). This indicates extremely weak drive capability, limiting its suitability to micropower sensing applications. Direct substitution in circuits requiring output current or dynamic load regulation—such as linear regulators or error amplifiers—is not feasible. Replacement may only be considered if the circuit relies solely on its reference voltage with no load demand.

2. TL431CLPRPG Substitution Conclusion The TL431CLPRPG matches the LM431BCZX in key specifications including voltage range, output current (100 mA), and cathode current (1 mA). The primary difference lies in its tolerance of ±2.2% versus the original’s ±1%. This lower initial accuracy may affect applications with stringent voltage precision requirements, such as high‑accuracy power supplies or measurement circuits. However, if the system design incorporates sufficient error margin or allows calibration, substitution is highly feasible. This makes it a suitable alternative in cost‑sensitive applications where precision requirements are relaxed.

Analysis ID: 06E5-92F1000

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