TS431IZT

Overview

The TS431IZT is a low-voltage, three-terminal adjustable shunt voltage reference manufactured by STMicroelectronics. It operates within an output voltage range of 1.24 V to 6 V and supports a cathode current range from 60 µA to 30 mA. The device features an initial accuracy of 2% and a temperature coefficient of 100 ppm/°C. It is housed in a TO-92-3 through-hole package with a maximum input voltage of 10 V. The component functions reliably across an operating temperature range of -40°C to +125°C.

Feature Summary

• Adjustable shunt voltage reference topology allowing output setting between 1.24 V and 6 V via external resistors
• Low voltage operation capability enabling use in applications requiring lower supply voltages than standard TL431 references
• Wide operating cathode current range supporting both low power standby and higher drive requirements
• High thermal stability with a specified temperature coefficient of 100 ppm/°C over the industrial temperature range

Applications

• Regulating 3.3 V switching power supplies when driving optocouplers
• Precision voltage reference circuits in portable electronic devices
• Battery-powered equipment requiring stable low-voltage references

Procurement Notes

Verify the specific suffix 'IZT' corresponds to the TO-92-3 through-hole package configuration rather than surface mount variants. Confirm that the 2% initial accuracy meets the design tolerance requirements for the target application. Ensure the 10 V maximum input voltage rating provides sufficient headroom for the circuit's supply rails. Check for RoHS compliance status as indicated in official documentation before finalizing procurement specifications.

Selection Notes

Select this component when a through-hole TO-92-3 package is required for adjustable shunt regulation. It serves as a direct functional alternative to the TL431 but offers improved performance at lower voltages starting from 1.24 V. Consider the 2% accuracy and 100 ppm/°C temperature coefficient against stricter precision requirements. Evaluate the 30 mA maximum cathode current limit to ensure it satisfies the load drive needs of the feedback network or optocoupler interface.

Part Context

The TS431 series represents STMicroelectronics' evolution of the widely adopted TL431 adjustable shunt reference. This family is designed to operate efficiently at lower voltages, making it suitable for modern low-power electronics. The TS431IZT specifically denotes the version packaged in a TO-92-3 leaded format, distinguishing it from surface-mount options like the SOT-23-5 variants within the same product line.

Replacement Considerations

Publicly confirmed substitute part numbers include TLV431AILPM and TLV431AILPR from Texas Instruments.