FAN431AZXA Replacement: KA431LZTA, TL1431IZT

Original Part

FAN431AZXA

onsemi

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

Alternative Part

KA431LZTA

onsemi

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

TL1431IZT

STMicroelectronics

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

1. KA431LZTA Substitution Conclusion The KA431LZTA can directly replace the FAN431AZXA, as both are shunt voltage references from the same series manufactured by onsemi. Key parameters—including output voltage range (2.495V–36V), output current (100mA), temperature coefficient (50ppm/°C), and package (TO-92-3)—are identical. The primary difference lies in the accuracy: the KA431LZTA offers ±0.5% tolerance, which is tighter than the original part’s ±1%. This provides improved voltage precision in the same application without requiring peripheral circuit adjustments, making the substitution fully compatible and risk-free.

2. TL1431IZT Substitution Conclusion The TL1431IZT exhibits partial parametric differences and should be evaluated carefully before substitution. Its nominal output voltage (2.5V) is slightly higher than the original part (2.495V), though its tolerance (±0.4%) is better. However, its temperature coefficient (100ppm/°C) is notably worse than the original (50ppm/°C), potentially doubling output voltage drift over wide temperature ranges and impacting applications with stringent thermal stability requirements. Furthermore, while both devices use a TO-92-3 outline, the specific variant (TO-226AC) may differ in pin arrangement compared to the original TO-226AA package. Pin‑to‑pin compatibility must be verified prior to replacement.

Analysis ID: 10D1-0543000

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