TL1431QD

Overview

The TL1431QD is a precision programmable shunt voltage reference manufactured by Texas Instruments, housed in an SOIC-8 surface-mount package. It provides an adjustable output voltage ranging from approximately 2.5V to 36V using two external resistors. The device features a 0.4% initial voltage tolerance and operates within a temperature range of -40°C to +125°C. Key electrical specifications include a maximum cathode current of 100mA, a typical output impedance of 0.2Ω, and a fast turn-on time of 500ns.

Feature Summary

• Precision adjustable shunt regulation with specified thermal stability across automotive temperature ranges
• Active output circuitry providing sharp turn-on characteristics for effective Zener diode replacement
• Internal compensation ensures stability without requiring an output capacitor between cathode and anode

Applications

• Adjustable voltage and current referencing
• Secondary side regulation in flyback switching mode power supplies (SMPS)
• Voltage monitoring systems
• Comparators with integrated reference

Procurement Notes

Verify the specific suffix 'QD' corresponds to the automotive grade (-40°C to 125°C) and SOIC-8 package configuration required for your design. Confirm that the 0.4% initial accuracy meets your system's total error budget requirements. Ensure proper ESD handling protocols are followed during assembly due to the sensitivity of the internal reference components.

Selection Notes

Select this component when high precision and wide operating temperature ranges are necessary compared to standard commercial variants. Consider the 100mA sink capability for applications requiring higher load currents than typical 20mA references. Evaluate the need for the SOIC-8 footprint against available board space and thermal dissipation constraints for your specific enclosure design.

Part Context

This part belongs to the TL1431 family of precision programmable references, which includes commercial (TL1431C), automotive (TL1431Q), and military (TL1431M) grades. The TL1431 series serves as a fundamental analog building block, combining an accurate voltage reference with an operational amplifier to function as a shunt regulator or error amplifier in various industrial and computing applications.

Replacement Considerations

TL1431QDRQ1

FAQ

Is the TL1431QD internally compensated?

Yes, the device is internally compensated to remain stable without an output capacitor between the cathode and anode pins.

What is the minimum cathode current required for regulation?

A minimum cathode current of 1mA is required for the device to enter the proper linear region and maintain regulation.