TL431BCD

Overview

The onsemi TL431BCD is a three-terminal programmable shunt regulator diode based on the TL431 family. It operates as a low temperature coefficient zener, providing a reference voltage adjustable from Vref (approximately 2.5V) to 36V using two external resistors. The device features a typical voltage reference tolerance of ±0.4% at 25°C and exhibits a low dynamic output impedance of 0.22 Ω. It supports a wide operating current range from 1.0 mA to 100 mA with a typical full-range temperature coefficient of 50 ppm/°C. The component is designed for temperature-compensated operation across its rated range.

Feature Summary

• Programmable output voltage adjustable via external resistors
• Low dynamic output impedance for stable regulation
• Temperature compensated for full-rated operating range
• Low output noise voltage characteristics

Applications

• Digital voltmeters
• Power supplies
• Op amp circuitry

Procurement Notes

Verify that the specific part number matches the required tolerance grade, as the 'B' suffix typically denotes ±0.4% accuracy. Confirm package availability and ensure compliance with RoHS standards if required by your design specifications. Cross-reference with manufacturer documentation to confirm pinout compatibility and thermal performance requirements for your specific PCB layout.

Selection Notes

Select this component when a precise, adjustable voltage reference is needed to replace standard Zener diodes in linear applications. The low dynamic impedance and temperature compensation make it suitable for circuits requiring high stability over varying conditions. Ensure the design allows for the necessary external resistor network to set the desired output voltage within the 36V maximum limit.

Part Context

This component belongs to the TL431 series of programmable precision references manufactured by onsemi. These devices are widely used in power management and signal conditioning circuits where a stable, adjustable reference voltage is critical. The series offers various tolerance grades and packaging options to suit different industrial and commercial application needs.

Replacement Considerations

Compatible substitutes include the TL431A (±0.5% tolerance) and TL431C (±1% tolerance). Other manufacturers such as Texas Instruments and Nexperia offer equivalent parts like the TL431IDBZR or NCV431 variants, provided they meet the same electrical specifications and package constraints.

FAQ

What is the typical dynamic output impedance of the TL431BCD?

The typical dynamic output impedance is 0.22 Ω.

How is the output voltage adjusted?

The output voltage is programmable from Vref to 36V using two external resistors.