1. AS431IAZTR-G1 Substitution Conclusion Direct substitution of the AS431IAZTR-G1 for the original part is not highly feasible and requires careful evaluation. The key differences are as follows: First, its reference voltage tolerance is ±0.5%, which is inferior to the original part's ±0.4%, resulting in lower initial output voltage accuracy. Second, its nominal temperature coefficient (Temp Coef) is not explicitly specified, whereas the original part is rated at 100ppm/°C. This introduces uncertainty regarding its output voltage drift performance over the full operating temperature range, which may be significantly worse than the original. Third, its minimum cathode operating current (Ikat) is 50µA, substantially lower than the original's 1mA. While this enables startup and operation at extremely low power, the dynamic response may differ in linear regulation circuits that require a minimum operating current. This device is only suitable for applications where initial accuracy and temperature stability are not critical. If used in precision reference or wide-temperature-range applications, there is a risk of performance degradation.