1. AS431IAZTR-G1 Substitution Conclusion Direct substitution is not readily feasible and warrants careful evaluation. This part exhibits significant deviations from the original specifications in key parameters: its accuracy is ±0.5%, inferior to the original’s ±0.4%, resulting in a larger initial error in reference voltage. The temperature coefficient is unspecified, introducing performance uncertainty and potentially higher voltage drift across a wide temperature range. Most critically, its cathode operating current is only 50µA, substantially lower than the original’s 1mA. This may prevent proper startup or stable operation under the original design’s minimum operating current conditions, posing a risk of circuit failure. Unless the application circuit is confirmed to operate correctly at very low cathode currents and has relaxed requirements for accuracy and temperature drift, direct substitution is not recommended.