TL431C

Overview

The TL431C is a three-terminal adjustable precision shunt regulator manufactured by TAEJIN. It provides a programmable output voltage ranging from the reference voltage of 2.495V up to 40V using two external resistors. The device guarantees a tight reference voltage tolerance of 0.5% and features a typical dynamic output impedance of 0.2Ω. It operates with a cathode current range of 0.5mA to 100mA and is characterized for operation across an ambient temperature range of -40°C to +125°C.

Feature Summary

• Programmable output voltage capability extending up to 40V via external resistor networks
• Guaranteed 0.5% reference voltage tolerance for high-precision applications
• Low dynamic output impedance typically measuring 0.2Ω
• Temperature compensated design ensuring stability over the full operating temperature range

Applications

• Shunt Regulator
• Precision High-Current Series Regulator
• High-Current Shunt Regulator
• Crowbar Circuit
• PWM Converter With Reference Voltage Monitor

Procurement Notes

Verify the specific package variant required, as the TL431C is available in TO-92 (Bulk or Tape), SOT-23-3L, and SOT-89-3L configurations. Confirm that the 0.5% tolerance grade matches the circuit requirements, as other grades like TL431A (1%) exist. Ensure the selected package aligns with the thermal dissipation needs of the application within the specified operating temperature range.

Selection Notes

Select this component when a precise, low-cost voltage reference is needed to replace Zener diodes in linear or switching power supplies. The TL431C is suitable for designs requiring a sharp turn-on characteristic and low output noise. Consider the maximum cathode voltage rating of 42V and the continuous current limits when designing the feedback network to ensure reliable regulation under all load conditions.

Part Context

The TL431 series serves as a widely adopted standard for adjustable shunt regulation in power management circuits. Manufactured by TAEJIN, this specific part belongs to the programmable precision reference family. It functions as a critical control element in feedback loops for switching regulators and linear power supplies, offering thermal stability comparable to more expensive bandgap references.

Replacement Considerations

Compatible substitutes include the TL431A (1% tolerance) and TL431 (2% tolerance) from the same manufacturer, provided the tighter 0.5% accuracy is not strictly required. Other manufacturers' TL431 variants are generally pin-compatible but require verification of absolute maximum ratings and electrical characteristics against the datasheet specifications.