NCP431BCSNT1G Replacement: KA431SAMF2TF, TL432AIDBZRG4

Original Part

NCP431BCSNT1G

onsemi

Shunt Voltage Reference IC Adjustable 2.5V 36 VV ±0.5% 40 µA SOT-23-3 (TO-236)

Alternative Part

KA431SAMF2TF

onsemi

Shunt Voltage Reference IC Adjustable 2.495V 36 VV ±1% 100 mA SOT-23F-3

TL432AIDBZRG4

Texas Instruments

Shunt Voltage Reference IC Adjustable 2.495V 36 VV ±1% 100 mA SOT-23-3

1. KA431SAMF2TF Substitution Conclusion As a newer part from the same manufacturer (onsemi), the KA431SAMF2TF is compatible in basic functionality and package (a SOT-23 variant), making it a direct drop-in replacement. The key differences are: the nominal output voltage shifts from 2.5V to 2.495V, the initial accuracy relaxes from ±0.5% to ±1%, and the minimum cathode operating current (Iref) increases from 100µA to 1mA. Consequently, this substitution introduces a systematic offset of approximately 5mV in the system's reference voltage. For high-precision voltage setpoint circuits, such as precision ADC/DAC references, this offset may introduce additional error. Furthermore, the wider initial tolerance (±25mV vs. ±12.5mV) impacts the predictability of overall system accuracy. The significantly higher minimum cathode current requirement is particularly critical; in circuits demanding ultra-low standby power, this substitute will increase unnecessary quiescent current, rendering it unsuitable for power-sensitive applications.

2. TL432AIDBZRG4 Substitution Conclusion The TL432AIDBZRG4 from Texas Instruments is fully compatible in basic functionality and package, serving as a viable direct replacement. Its differences are similar: the nominal output voltage is also 2.495V with an accuracy of ±1%. However, its temperature coefficient (Temp Coef) parameter is not specified in the provided data, and its minimum cathode operating current (Iref) is 80µA. Like the KA431SAMF2TF, substitution will result in the same ~5mV system voltage offset and the effects of a wider total accuracy tolerance. The unspecified temperature coefficient presents a potential risk. If its temperature drift is significantly higher than 50ppm/°C, the output voltage stability across the full operating temperature range will degrade, potentially making it unsuitable for wide-temperature or high-stability applications. On a positive note, its 80µA cathode current requirement is closer to the original part's 40µA, offering an advantage over the KA431SAMF2TF in low-power designs.

Analysis ID: C061-49A1000

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