TL431AILPRPG Replacement: KA431LZTA, TL1431ACZ-AP

Original Part

TL431AILPRPG

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

TL1431ACZ-AP

STMicroelectronics

Shunt Voltage Reference IC Adjustable 2.5V 36 VV ±0.25% 100 mA TO-92-3

1. KA431LZTA Substitution Conclusion The KA431LZTA is a high-precision, drop-in replacement for the original part (TL431AILPRPG). Both are manufactured by onsemi and share identical packages, core electrical parameters (reference voltage, operating voltage range, output current), and typical temperature drift characteristics. The primary distinction is that the KA431LZTA features improved initial accuracy (tolerance), tightened from ±1% to ±0.5%. This results in lower output voltage dispersion at room temperature, offering enhanced circuit consistency and precision, making it a performance-upgraded substitute. In the vast majority of applications, this difference does not introduce compatibility issues, allowing for direct replacement to achieve superior accuracy performance.

2. TL1431ACZ-AP Substitution Conclusion The TL1431ACZ-AP requires critical parameter evaluation as a potential substitute and is not a direct drop-in replacement. While it offers superior reference voltage (2.5V vs. 2.495V) and accuracy (±0.25%), two key differences must be considered. First, its temperature coefficient shifts from a typical 50ppm/°C to 90ppm/°C (maximum), leading to a larger variation in output voltage over temperature. This may result in inferior stability compared to the original part in wide-temperature-range applications. Second, the required cathode operating current is reduced from 1mA to 600µA. This is beneficial for lowering system power consumption; however, it is essential to verify that the original circuit can provide stable bias at this lower current level. This substitute may be suitable for cost-sensitive, high-precision applications where temperature stability is not critical and the bias current requirement is met. Otherwise, a careful evaluation is necessary.

Analysis ID: 9655-F75A000

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