TL431BL3T

Overview

The TL431BL3T is an adjustable shunt voltage reference manufactured by STMicroelectronics. It provides a guaranteed temperature stability over the entire operating temperature range. The output voltage can be set to any value between 2.5 V and 36 V using two external resistors. The device operates with a wide current range from 1 mA to 100 mA, featuring a typical dynamic impedance of 0.22 Ω. It offers high precision with a voltage tolerance of ±0.5% at 25 °C for the 'B' grade version.

Feature Summary

• Adjustable output voltage capability ranging from 2.5 V to 36 V via external resistor divider
• High precision voltage accuracy with ±0.5% tolerance at 25 °C
• Wide cathode current operating range supporting sink currents from 1 mA to 100 mA
• Low typical dynamic output impedance ensuring stable regulation performance

Applications

• Precision voltage references in power supply circuits
• Programmable linear regulators
• Optocoupler driver circuits for feedback control
• Battery chargers requiring accurate voltage monitoring

Procurement Notes

Verify the specific suffix 'L3T' indicates the SOT-23 surface-mount package configuration when sourcing. Confirm that the 'B' designation corresponds to the ±0.5% initial accuracy grade required for your application. Ensure the supplier provides documentation confirming the component meets the standard TL431 electrical specifications for shunt regulation.

Selection Notes

Select this component when a compact SOT-23 footprint is required for space-constrained designs. Choose the TL431BL3T specifically for applications demanding higher initial voltage accuracy compared to standard grade versions. Consider the 1 mA minimum operating current requirement when designing low-power circuits to ensure proper regulation.

Part Context

This part belongs to the widely used TL431 family of programmable shunt regulators. It serves as a cost-effective alternative to Zener diodes, offering superior temperature stability and lower dynamic impedance. The device is functionally compatible with industry-standard equivalents, facilitating easy replacement in existing designs while providing improved performance characteristics.

Replacement Considerations

Compatible substitutes include the TS2431 and TLVH431 series from STMicroelectronics. Other generic equivalents such as the KA431 or REF43 may be considered if pinout and electrical parameters match. Verify that any replacement maintains the same SOT-23 package and ±0.5% accuracy grade.