TL1431CLPE3 Replacement: LM431CCZ, KA431AZBU

Original Part

TL1431CLPE3

Texas Instruments

Shunt Voltage Reference IC Adjustable 2.5V 36 VV ±0.4% 100 mA TO-92-3

Alternative Part

LM431CCZ

onsemi

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

KA431AZBU

onsemi

Shunt Voltage Reference IC Adjustable 2.495V 36 VV ±1% 100 mA TO-92-3

1. LM431CCZ Substitution Conclusion The LM431CCZ can serve as a replacement for the TL1431CLPE3, though several differences should be noted. The reference voltage decreases slightly from 2.5 V to 2.495 V, while the tolerance relaxes from ±0.4% to ±0.5%. These changes may result in a minor reduction in initial output voltage accuracy, potentially introducing small errors in precision applications. On the other hand, the LM431CCZ offers a specified typical temperature coefficient of 50 ppm/°C, whereas the original part does not provide a guaranteed value—giving the substitute a clearer assurance regarding temperature stability. For most general-purpose circuits, such as power supply feedback or voltage monitoring, these variations can be compensated by adjusting external resistors. Given the pin‑to‑pin compatibility, substitution is generally acceptable. However, in designs demanding high‑precision voltage references, the impact of voltage offset and wider tolerance on system performance should be carefully evaluated.

2. KA431AZBU Substitution Conclusion The KA431AZBU is a possible replacement for the TL1431CLPE3, but with notable differences. The reference voltage is 2.495 V instead of 2.5 V, and the tolerance widens from ±0.4% to ±1%. This implies lower reference accuracy, which could lead to greater output voltage error in high‑precision applications. That said, the KA431AZBU provides a specified typical temperature coefficient of 50 ppm/°C—an improvement over the unspecified characteristic of the original part, offering better defined temperature stability. In less critical applications, such as low‑cost power supplies or non‑critical voltage references, the package and basic parameters remain compatible, making substitution feasible. However, the wider tolerance must be accepted, and this substitute may not be suitable for circuits with stringent requirements on reference voltage accuracy.

Analysis ID: 7718-6DF4000

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