TL431ACDR2

Overview

The TL431ACDR2 is a three-terminal programmable shunt regulator diode from onsemi, housed in an 8-pin SOIC package. It operates as a low temperature coefficient zener reference, programmable from Vref to 36 V using two external resistors. The device supports a cathode current range of 1.0 mA to 100 mA with a typical dynamic impedance of 0.22 Ω. It features a reference voltage tolerance of ±1% and a typical full-range temperature coefficient of 50 ppm/°C. Designed for surface mount applications, it functions effectively as a positive or negative voltage reference.

Feature Summary

• Programmable output voltage capability up to 36 V via external resistor divider
• Temperature compensated operation across the rated ambient temperature range
• Low dynamic output impedance for stable regulation performance
• Wide sink current operating range suitable for various load conditions

Applications

• Feedback control for driving optocouplers in power supplies
• Digital voltmeter reference circuits
• Op amp circuitry requiring stable voltage references
• Constant current source and sink implementations

Procurement Notes

Verify the specific suffix 'R2' corresponds to the tape and reel shipping configuration required for automated assembly processes. Confirm that the 'AC' designation aligns with the necessary ±1% initial accuracy tolerance for the target design. Ensure the SOIC-8 package dimensions match the printed circuit board footprint constraints. Check for RoHS compliance status if environmental regulations apply to the final product deployment.

Selection Notes

Select this component when a precise, adjustable voltage reference is needed within a compact surface-mount form factor. The ±1% tolerance suits applications demanding higher accuracy than standard Zener diodes provide. Consider the thermal resistance characteristics if significant power dissipation is expected. Verify stability requirements against load capacitance limits to prevent oscillation in feedback loops.

Part Context

This device belongs to the TL431 series of programmable precision references manufactured by onsemi. It serves as a direct replacement for traditional Zener diodes in many analog and digital circuits. The series includes variants with different tolerances and temperature ranges, such as the NCV431A for automotive use. The SOIC-8 package offers a balance between thermal performance and space efficiency for consumer and industrial electronics.

Replacement Considerations

Compatible substitutes include the TL431ACDR2G (Pb-free version) and other TL431 series variants like TL431BCDR2G for tighter tolerance needs. Cross-reference with LM431 or KA431 equivalents if pin-compatible alternatives are required. Ensure any replacement maintains the same 3-terminal shunt regulator topology and voltage programming range.