TL431AIZ

Overview

The TL431AIZ is a three-terminal programmable shunt voltage reference manufactured by STMicroelectronics. It operates within an input voltage range of 2.5 V to 36 V and provides an adjustable output voltage from 2.495 V to 36 V using two external resistors. The device features an initial accuracy tolerance of ±1% and a typical temperature coefficient of 100 ppm/°C. It supports a cathode current range from 1 mA to 100 mA with a maximum supply voltage of 37 V. Designed for through-hole mounting, it utilizes the TO-92-3 package and functions reliably across an industrial temperature range of -40°C to +105°C.

Feature Summary

• Programmable output voltage capability set between the internal reference threshold and the maximum supply limit via external resistor dividers.
• Guaranteed thermal stability over the full rated operating temperature range with low dynamic output impedance characteristics.
• Fast turn-on response and low output noise voltage suitable for precision regulation applications.

Applications

• Precision voltage references in power supply circuits
• Programmable linear regulators
• Remote sensing feedback loops

Procurement Notes

Verify the specific suffix 'I' indicates the industrial temperature grade (-40°C to +105°C) and 'Z' denotes the lead-free RoHS-compliant status as per STMicroelectronics documentation. Confirm the package type matches the required TO-92-3 through-hole footprint for your PCB layout. Ensure the selected component meets the required ±1% initial accuracy specification for your design.

Selection Notes

Select this component when a high-precision, adjustable shunt regulator is required within the TO-92-3 form factor. The ±1% tolerance offers tighter accuracy than standard 2% variants. Consider the 100 mA sink current capability against load requirements. Verify that the 100 ppm/°C temperature coefficient aligns with the thermal stability needs of the application environment.

Part Context

This part belongs to the TL431 family of programmable shunt regulators, widely used as voltage references and error amplifiers. The TL431AIZ specifically represents the industry-standard version with improved accuracy compared to basic models. It serves as a cost-effective alternative to Zener diodes in feedback networks where precise voltage setting and stability are critical.

Replacement Considerations

Cross-reference with other manufacturers offering TL431A equivalents in TO-92 packages. Verify pinout compatibility (Anode, Cathode, Reference) before substitution. Check if alternative parts meet the same ±1% accuracy and industrial temperature range specifications.

FAQ

What determines the output voltage range?

The output voltage is adjustable from approximately 2.495 V up to 36 V, determined by the ratio of two external resistors connected to the reference pin.

How does the TL431AIZ differ from the TL431BIZ?

The primary difference is the initial accuracy tolerance; the TL431AIZ guarantees ±1% accuracy, whereas the TL431BIZ typically offers ±2% accuracy.