TL431CPSR

Overview

The TL431CPSR is an adjustable precision shunt regulator manufactured by Texas Instruments, housed in a SOIC-8 surface-mount package. It operates within a cathode voltage range of 2.5V to 36V and provides an adjustable output reference voltage starting from 2.495V. The device features a maximum shunt current of 100mA and an initial accuracy of ±2%. It exhibits a temperature coefficient of 92 ppm/°C and functions reliably across an operating temperature range of -40°C to +125°C.

Feature Summary

• Provides precise programmable voltage reference functionality via external resistor divider
• Operates as a shunt regulator with high dynamic impedance characteristics
• Supports wide input voltage range up to 36V for flexible circuit integration

Applications

• Precision voltage reference sources in power supply circuits
• Programmable linear regulators and switching power supplies
• Comparator threshold setting and error amplifier feedback networks

Procurement Notes

Verify the specific suffix 'C' indicates the ±2% initial accuracy grade when sourcing replacements. Confirm the 'P' designation corresponds to the standard SOIC-8 package variant required for your PCB footprint. Ensure the 'S' suffix aligns with the reel packaging specification needed for automated assembly processes. Cross-reference the manufacturer part number against official TI documentation to confirm current production status and availability constraints.

Selection Notes

Select this component when a low-cost, adjustable shunt regulator with ±2% accuracy is sufficient for the application. Consider the SOIC-8 package dimensions for thermal management and board space constraints. Evaluate the 100mA current limit against peak load requirements. Compare against fixed-voltage references if a single setpoint is adequate, or higher-accuracy variants if tighter tolerance is necessary.

Part Context

This part belongs to the widely adopted TL431 family of programmable shunt regulators. It serves as a cost-effective alternative to Zener diodes, offering superior temperature stability and lower dynamic impedance. The device integrates a 2.495V internal bandgap reference with an operational amplifier to control the cathode-anode current path based on the voltage applied to the reference pin.

Replacement Considerations

Compatible substitutes include the LM431 series and generic equivalents such as KA431 or AZ431. Verify pinout compatibility and electrical specifications match before substitution. Ensure the replacement package matches the SOIC-8 form factor for direct board replacement.