TL431BQPK

Overview

The TL431BQPK is a three-terminal adjustable precision shunt regulator manufactured by Texas Instruments. It operates within an automotive temperature range of -40°C to 125°C and features a reference voltage tolerance of ±0.5% at 25°C. The device provides an adjustable output voltage range from the internal reference of approximately 2.495V up to 36V, set via two external resistors. It supports cathode currents between 1mA and 100mA with a typical dynamic impedance of 0.2Ω. Packaged in a SOT-89-3 (3+Tab) configuration, it is designed for applications requiring high thermal stability and low noise.

Feature Summary

• Automotive-grade qualification ensuring specified thermal stability across wide operating temperatures
• High initial accuracy with 0.5% reference voltage tolerance at 25 degrees Celsius
• Low output noise characteristics suitable for sensitive analog circuits
• Wide adjustable output voltage range utilizing simple external resistor networks

Applications

• Board-level voltage regulation in automotive electronic systems
• Precision power supply references for switching converters
• Voltage monitoring and threshold detection circuits
• Linear regulator feedback loops requiring stable reference voltages

Procurement Notes

Verify that the specific suffix QPK confirms automotive grade classification and SOT-89 packaging. Confirm RoHS compliance status and lead times through authorized distributors. Ensure the sourcing channel provides traceability documentation required for automotive assembly processes. Check for any recent product change notices affecting pinout or material composition.

Selection Notes

Select this component when automotive reliability standards are mandatory alongside tight voltage accuracy requirements. The 0.5% tolerance distinguishes it from standard commercial grades. Consider the SOT-89 package for thermal dissipation needs compared to smaller surface-mount options. Evaluate the 100mA current capability against load requirements to ensure adequate headroom for regulation stability.

Part Context

This part belongs to the TL431 family of programmable shunt regulators. The 'B' suffix indicates the 0.5% accuracy grade, while 'Q' denotes automotive qualification. The 'PK' suffix specifies the SOT-89 tape and reel packaging. This variant integrates the precision reference functionality into a compact form factor suitable for dense automotive PCB layouts.

Replacement Considerations

Compatible substitutes include other automotive-qualified TL431 variants with matching accuracy grades. Verify pin compatibility and thermal performance before substitution. Cross-reference with equivalent parts from other manufacturers holding AEC-Q100 certification.