TL431BILPE3 Replacement: TL431BVLPG, TL1431IZ

Original Part

TL431BILPE3

Texas Instruments

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

Alternative Part

TL431BVLPG

onsemi

Shunt Voltage Reference IC Adjustable 2.495V 36 VV ±0.4% 100 mA TO-92 (TO-226)

TL1431IZ

STMicroelectronics

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

1. TL431BVLPG Substitution Conclusion From the perspective of core electrical parameters and functionality, the TL431BVLPG is a viable direct substitute for the TL431BILPE3. Both share the same adjustable output voltage range (2.495V to 36V) and output current capability (100mA). The primary differences are as follows: the TL431BVLPG offers superior initial accuracy (±0.4% vs. ±0.5%), which is beneficial for improving the absolute accuracy of the reference voltage. Its typical operating cathode current is higher (1mA vs. 700µA). During substitution, it is crucial to ensure the circuit can provide at least 1mA of bias current to this device; otherwise, it may malfunction or exhibit degraded accuracy. Additionally, it specifies a clear typical temperature drift coefficient (50ppm/°C). Provided the power supply circuit can meet its minimum operating current requirement, substitution is feasible and typically results in a slight improvement in accuracy.

2. TL1431IZ Substitution Conclusion Direct substitution with the TL1431IZ requires extra caution. While it is functionally identical and also features an accuracy of ±0.4%, several key differences exist: Its nominal reference voltage is 2.5V (a nominal 5mV difference from the original part's 2.495V, even though the ±0.4% tolerance bands overlap). This may introduce a subtle systematic offset in the system's output voltage. Its temperature coefficient is inferior (100ppm/°C), meaning circuit output voltage stability over a wide temperature range may not match that of the original part. Its typical cathode current is also 1mA, presenting the same bias circuit adaptation issue as the TL431BVLPG. Furthermore, its package description is questionable (listed as TO-92-2, which conflicts with the pin count of TO-92-3 used by other variants—this is likely a datasheet typo, but pin compatibility must be verified against physical samples or official drawings). Direct substitution is not recommended unless the application is insensitive to absolute voltage value and temperature drift, and package pin compatibility has been conclusively verified.

Analysis ID: 540A-0527000

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