1. TL431CLP Substitution Conclusion Proceed with caution, with key attention to the risk of accuracy degradation. The core difference between the TL431CLP and the original part lies in the reference voltage tolerance, which is relaxed from ±1% to ±2.2%. Furthermore, its temperature coefficient is not explicitly specified. In applications where the original design relies on the ±1% initial accuracy (e.g., precision power supply references, ADC reference voltages), direct substitution may cause the system's output voltage accuracy to exceed specifications, impacting overall performance metrics. The absence of temperature coefficient data also introduces uncertainty regarding output voltage drift characteristics over a wide temperature range, making it unsuitable for applications demanding high-temperature stability. If the application has relaxed requirements for the absolute accuracy of the reference voltage (e.g., general error amplification, over-voltage protection) and operates within a limited temperature range, substitution can be considered based on identical package and basic electrical parameters.