TL431ACLPRE3 Replacement: AZ431AZ-ATRE1, AZ431BZ-ATRE1

Original Part

TL431ACLPRE3

Texas Instruments

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

Alternative Part

AZ431AZ-ATRE1

Diodes Incorporated

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

AZ431BZ-ATRE1

Diodes Incorporated

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

1. AZ431AZ-ATRE1 Substitution Conclusion The AZ431AZ-ATRE1 is generally compatible in terms of electrical performance and package footprint and can serve as a substitute for the TL431ACLPRE3. However, its higher required cathode operating current is a key limitation. The primary advantages of this part are its superior initial accuracy (±0.4%) compared to the Original Part (±1%), and its specified temperature coefficient (20ppm/°C typical). Under equivalent conditions, it can provide a more precise and stable reference voltage. Its "cathode current" parameter is specified at 1mA, significantly higher than the Original Part's 600µA. After substitution, the circuit must therefore supply a greater minimum operating current to maintain proper reference operation. If the original circuit operates near the cathode current threshold (e.g., in a low-power design), direct replacement may prevent the reference from starting up or cause unstable operation. The feasibility of substitution hinges on whether the original design can guarantee a cathode current greater than 1mA under all minimum operating conditions.

2. AZ431BZ-ATRE1 Substitution Conclusion The AZ431BZ-ATRE1 also offers pin-to-pin and basic electrical compatibility, making it a potential alternative for the TL431ACLPRE3, with the same need to carefully consider its cathode current requirement. The initial accuracy of this part (±0.8%) is in the same order of magnitude as, or slightly better than, the Original Part (±1%), indicating largely equivalent performance. It also provides a specified temperature coefficient (20ppm/°C typical), which is a clear parameter for applications demanding temperature stability. Similar to the AZ431AZ part, its 1mA cathode current requirement is the primary constraint during substitution, necessitating sufficient drive capability margin in the original circuit. Provided the original circuit is confirmed to supply adequate cathode current (>1mA), this part can be used as a direct substitute with comparable performance parameters.

Analysis ID: E545-EA5A000

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