TL431ACLPRAG Replacement: KA431LZTA, TL1431ACZ-AP

Original Part

TL431ACLPRAG

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 This is a perfect, drop-in replacement that constitutes a performance upgrade. The KA431LZTA, like the original TL431ACLPRAG, is an ON Semiconductor product. It is identical to the original in all core electrical parameters (2.495V reference voltage, operating voltage range, 100mA output current) and physical package (TO-92-3). The key improvement is its initial tolerance, which is tightened from ±1% to ±0.5%, providing higher output voltage accuracy and consistency. Other critical characteristics, such as the temperature coefficient (50ppm/°C), remain unchanged. Disregarding cost, this substitution not only meets all original design requirements but also enhances system precision.

2. TL1431ACZ-AP Substitution Conclusion This device can serve as a functional replacement in most applications, but it is not an unconditional drop-in substitute due to several key parametric differences that require attention. The TL1431ACZ-AP is pin-compatible (TO-92-3) and shares the core functionality. However, there are notable variances: firstly, its initial tolerance is superior at ±0.25%. Secondly, its nominal reference voltage is 2.5V (vs. the original part's 2.495V). While this difference is minor, it necessitates verification in circuits with stringent absolute voltage requirements. The most significant deviation is its temperature coefficient of 90ppm/°C, which is substantially higher than the original part's typical 50ppm/°C. This results in greater output voltage drift over temperature, potentially affecting performance in applications demanding high temperature stability. On a positive note, its lower cathode operating current (600µA) benefits low-power designs. The feasibility of this substitution ultimately depends on the specific application's sensitivity to absolute voltage value and temperature stability.

Analysis ID: 37A3-9CFC000

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