TL431AILPME3 Replacement: AZ431BZ-ATRE1, AS431BZTR-E1

Original Part

TL431AILPME3

Texas Instruments

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

Alternative Part

AZ431BZ-ATRE1

Diodes Incorporated

Shunt Voltage Reference IC Adjustable 2.5V 36 VV ±0.8% 100 mA TO-92

AS431BZTR-E1

Diodes Incorporated

Shunt Voltage Reference IC Adjustable 2.5V 36 VV ±1% 100 mA TO-92

1. AZ431BZ-ATRE1 Substitution Conclusion This device can be used as a direct replacement. However, potential impacts on circuit power consumption and stability due to differences in cathode current must be considered. Compared to the original TL431AILPME3, the AZ431BZ-ATRE1 is fully compatible in core functionality (adjustable 2.5V reference, 36V voltage rating, 100mA shunt capability) and package. Key differences include higher initial accuracy (±0.8% vs. ±1%) and a specified lower temperature coefficient (20ppm/°C), offering more stable and precise reference voltage over a wide temperature range, which constitutes a performance upgrade. Its typical cathode operating current is 1mA, significantly higher than the original's 700µA. Under the same upper bias resistor conditions, this will increase the device's own power dissipation, potentially affecting overall system efficiency or temperature rise. The original circuit must be verified to provide sufficient drive current, and thermal effects should be evaluated during design.

2. AS431BZTR-E1 Substitution Conclusion This device is a direct, functionally equivalent, and more economical alternative. Similar attention must be paid to the cathode current difference. The AS431BZTR-E1 is fully consistent with the original TL431AILPME3 in key electrical parameters (adjustable reference, voltage range, output current, ±1% accuracy) and package, making it a direct pin-to-pin replacement. A key difference is its specified typical temperature coefficient (20ppm/°C), which is not documented for the original part. This suggests the AS431BZTR-E1 may offer superior, or at least more predictable, temperature drift performance. Similar to the AZ431 variant, its cathode operating current (1mA) is also higher than the original's (700µA). After direct substitution, the static current flowing through the upper bias resistor and the device itself will increase, potentially leading to unnecessary power loss. This should be calculated for volume applications or in low-power designs.

Analysis ID: A118-8F50000

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