AS431IAZTR-G1 Replacement: KA431LZTA, FAN431AZXA

Original Part

AS431IAZTR-G1

Diodes Incorporated

Shunt Voltage Reference IC Adjustable 2.5V 36 VV ±0.5% 100 mA TO-92

Alternative Part

KA431LZTA

onsemi

Shunt Voltage Reference IC Adjustable 2.495V 36 VV ±0.5% 100 mA TO-92-3

FAN431AZXA

onsemi

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

1. KA431LZTA Substitution Conclusion The KA431LZTA can serve as a direct and performance-equivalent substitute for the AS431IAZTR-G1. The differences are as follows: the reference voltage nominal value shifts from 2.5V to 2.495V. This minor deviation can generally be compensated by the external resistor network in the vast majority of application circuits, with no impact on functionality. A typical temperature coefficient parameter (50ppm/°C) is specified, providing defined and improved voltage stability over a wide temperature range, which is superior to the original part where this parameter was not explicitly specified. The cathode operating current increases from 50µA to 1mA. This results in higher device self-power consumption while regulating, necessitating re-evaluation for ultra-low-power designs. However, for general-purpose designs, it enables stable operation over a wider dynamic current range. In summary, for non-extreme low-power applications, the KA431LZTA is an electrically compatible and upgraded alternative with better-defined temperature drift performance.

2. FAN431AZXA Substitution Conclusion The FAN431AZXA can function as a pin-compatible but downgraded-precision substitute for the AS431IAZTR-G1, suitable for applications where initial accuracy is not critical. Its differences from the original part include: the reference voltage nominal value is also 2.495V, with adjustable deviation; its initial accuracy tolerance is ±1%, lower than the original part's ±0.5%. This means a greater dispersion of the actual output voltage relative to the nominal value at production, potentially making it unsuitable for detection circuits requiring high absolute voltage accuracy. It shares the same typical temperature drift of 50ppm/°C and a cathode operating current of 1mA, matching the KA431LZTA in these aspects. This part is suitable for cost-sensitive applications that allow looser voltage accuracy (e.g., using it as a feedback threshold rather than a precision reference). When substituting, it is essential to verify that the system accuracy meets the requirements after this downgrade.

Analysis ID: 0A01-B439000

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