2. AZ431AZ-ATRG1 Substitution Conclusion Similarly, direct substitution is not advised, as it shares the same limitation as the AS431BZTR-G1. While it offers significant advantages over the original part in both initial tolerance (±0.4% vs. ±1%) and temperature coefficient (20ppm/°C vs. 50ppm/°C), promising a more accurate and stable reference voltage, the substantial gap in cathode current rating (1 mA vs. 100 mA) remains an insurmountable obstacle. It is unsuitable for any application requiring the reference to source or shunt appreciable current. Its performance benefits cannot be realized under the constraint of insufficient current capability. General Note: There may be a labeling ambiguity in the "Current - Output" parameter in the datasheet you provided. For shunt references, the key parameter is "Current - Cathode" (i.e., maximum operating current). The original part's 100 mA rating is typical for such devices, while the 1 mA specification for the Diodes parts is more common. Prior to substitution, it is essential to verify the actual current flowing through the reference's cathode in the application circuit. Substitution may only be considered if this current is significantly less than 1 mA; otherwise, a different part must be selected.