1. AS431BZTR-E1 Substitution Conclusion From the perspective of key electrical parameters and package, the AS431BZTR-E1 serves as a viable drop-in replacement. The differences are as follows: the reference voltage nominal value shifts from 2.495V to 2.5V (though both remain within a ±1% tolerance band, meaning their actual min/max ranges may fully overlap), and the temperature coefficient is significantly improved from a typical 50ppm/°C to a typical 20ppm/°C. For the vast majority of application circuits where the absolute accuracy of the reference voltage is not critical (e.g., accepting ±1% tolerance), the two parts are pin-to-pin compatible. Furthermore, the substitute device will offer markedly superior temperature stability (temperature drift) performance compared to the original part, constituting a positive enhancement. However, if the circuit design critically depends on the precise 2.495V nominal value for calculations without sufficient design margin, system accuracy may require re-verification.