TL1431CZ-AP Replacement: KA431LZTA, LM431CCZ

Original Part

TL1431CZ-AP

STMicroelectronics

Shunt Voltage Reference IC Adjustable 2.5V 36 VV ±0.4% 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

LM431CCZ

onsemi

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

1. KA431LZTA Substitution Conclusion The KA431LZTA can serve as a functional substitute for the TL1431CZ-AP, though minor differences in initial accuracy and nominal voltage must be considered. Specifically, the KA431LZTA offers an initial accuracy of ±0.5%, which is slightly wider than the ±0.4% of the original part, leading to somewhat greater output voltage dispersion at room temperature. Its typical temperature coefficient is 50 ppm/°C, notably better than the 90 ppm/°C of the original device, meaning the KA431LZTA exhibits lower output variation and better stability over a wide temperature range. The nominal reference voltage is 2.495 V, a 5 mV deviation from the original 2.5 V; this requires verification that the downstream circuit—such as divider resistors, comparator thresholds, or ADC reference—can tolerate the slight offset. Provided the application is not sensitive to the 0.1% absolute accuracy difference and can accept a 2.495 V reference, the KA431LZTA, with its identical package, adjustment range, and operating current, represents a substitute with superior temperature drift performance.

2. LM431CCZ Substitution Conclusion The LM431CCZ is a highly viable direct replacement for the TL1431CZ-AP, sharing the same core differences as the KA431LZTA. It also features ±0.5% initial accuracy, a 2.495 V nominal voltage, and a typical temperature coefficient of 50 ppm/°C. In applications demanding extremely tight room‑temperature accuracy (better than 0.5%), replacement may require tighter screening or calibration. However, in environments with significant temperature variation, the LM431CCZ’s lower temperature coefficient can result in overall performance that exceeds the original part. As an industry‑standard “431” series device, the LM431CCZ is fully compatible with the original in function, package, operating voltage, and current range. Therefore, in the vast majority of applications where reference voltage absolute accuracy need not exceed 0.5%, it can be used as a drop‑in replacement without circuit modification, while offering improved temperature stability.

Analysis ID: 4E12-CFDB000

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