TL431IZ Replacement: LM431AIZ, LM431CCZ

Original Part

TL431IZ

STMicroelectronics

Shunt Voltage Reference IC Adjustable 2.495V 36 VV ±2.21% 100 mA TO-92-3

Alternative Part

LM431AIZ

onsemi

Shunt Voltage Reference IC Adjustable 2.5V 36 VV ±2% 100 mA TO-92-3

LM431CCZ

onsemi

Shunt Voltage Reference IC Adjustable 2.495V 36 VV ±0.5% 100 mA TO-92-3

1. LM431AIZ Substitution Conclusion From the perspective of fundamental functionality and package, the LM431AIZ can serve as a direct substitute for the TL431IZ. Both are adjustable shunt references in a TO-92-3 package, with key parameters such as output voltage range (2.5V/2.495V~36V), output current capability (100mA), and minimum cathode current (1mA) being fully compatible. The differences lie in the initial accuracy (±2% vs. ±2.21%) and the temperature coefficient (Typ. 50ppm/°C vs. unspecified). The LM431AIZ offers slightly better output voltage accuracy at room temperature compared to the original part and provides a specified typical temperature drift parameter. This facilitates more precise system-level temperature stability analysis. Therefore, for the vast majority of applications where stringent reference accuracy is not critical—such as power supply feedback or over-voltage protection circuits—the LM431AIZ is a qualified substitute with equivalent or slightly superior performance.

2. LM431CCZ Substitution Conclusion The LM431CCZ represents a high-performance, direct replacement option. It is fully compatible with the TL431IZ in terms of package and key electrical characteristics (output voltage, current capability). The most significant technical differentiators are its superior initial accuracy (±0.5%) and its well-defined typical temperature coefficient (50ppm/°C). The LM431CCZ provides substantially higher output voltage accuracy and overall temperature stability than the original component. This can markedly enhance the performance of systems reliant on a precise reference voltage, such as precision power supplies or measurement circuits. The LM431CCZ is not merely a viable substitute but constitutes a performance upgrade. It is particularly suited for applications demanding higher reference voltage accuracy and stability, though it typically comes at a higher cost than standard-accuracy variants.

Analysis ID: 8811-9544000

Based on part parameters and for reference only. Not to be used for procurement or production.