1. LM431AIZ Substitution Conclusion The LM431AIZ can serve as a replacement for the TL431ILP, as both are 36V, 100mA adjustable shunt voltage regulators with fully compatible packages and pinouts. The differences are as follows: the LM431AIZ has a nominal reference voltage of 2.5V (compared to 2.495V for the TL431ILP), though the actual deviation is negligible and does not affect typical circuit design. Its initial accuracy is ±2%, which is slightly better than the ±2.2% of the TL431ILP, potentially resulting in an output voltage closer to the nominal value. Most importantly, the LM431AIZ specifies a typical temperature coefficient of 50ppm/°C, while the TL431ILP does not provide this data. In wide-temperature-range applications, the LM431AIZ offers more predictable output voltage performance over temperature and potentially superior stability. Overall, the electrical characteristics of the two devices are highly consistent. The LM431AIZ does not degrade in key parameters and provides clearer specifications in certain areas, making it a suitable direct substitute.