TL431AF

Overview

The TL431AF is a programmable precision shunt regulator manufactured by Tae Jin Technology. It provides an adjustable output voltage ranging from 2.495 V to 40 V, set via two external resistors. The device features a typical dynamic output impedance of 0.2 Ω and supports a continuous cathode current range of 100 mA to 150 mA. It guarantees a reference voltage tolerance of 0.5% and operates over a full rate temperature range with an equivalent coefficient of 50 PPM/°C. Minimum cathode current for regulation is 500 µA.

Feature Summary

• Programmable output voltage capability up to 40 V using external resistors
• High precision with guaranteed 0.5% reference voltage tolerance
• Low dynamic output impedance for stable regulation performance
• Temperature compensated operation across the full operating range

Applications

• Shunt regulator circuits
• Precision high-current series regulators
• High-current shunt regulators
• Voltage and current references

Procurement Notes

Verify the specific manufacturer designation as Tae Jin Technology when sourcing this component. Confirm package availability matches system requirements, typically TO-92, SOT-89, or SOT-23. Ensure the 0.5% tolerance grade (indicated by 'F') aligns with design accuracy needs. Cross-reference datasheets for thermal characteristics and pinout configurations to prevent integration errors during procurement.

Selection Notes

Select the TL431AF when high initial accuracy is required, specifically the 0.5% tolerance grade. This variant offers superior stability compared to standard grades. Consider the 50 PPM/°C temperature coefficient for applications requiring consistent performance across varying thermal conditions. Verify that the 150 mA maximum sink current meets the load requirements of the target circuit design.

Part Context

The TL431AF belongs to the TL431 family of three-terminal programmable shunt regulators. These devices serve as versatile alternatives to Zener diodes, offering adjustable voltage thresholds and higher current handling capabilities. The family includes various tolerance grades and temperature ranges, with the AF suffix denoting the specific 0.5% accuracy and extended temperature specifications provided by Tae Jin Technology.

Replacement Considerations

Compatible substitutes include TL431BFDT and TL431BMFDT for similar precision levels. Other manufacturers offer equivalents such as NXP TL431AFDT or STMicroelectronics TL431AI variants, ensuring pin compatibility and electrical parameter alignment.