TL431AFDT/8R

Overview

The TL431AFDT/8R is an adjustable precision shunt voltage reference manufactured by Nexperia USA Inc. It operates within a cathode-to-anode voltage range of 2.5 V to 36 V and provides a nominal reference voltage of 2.495 V with a tolerance of ±1%. The device supports a sink current capability from 1 mA to 100 mA and functions reliably across an ambient temperature range of -40°C to 125°C. Packaged in the SOT-323 (SC-70) surface-mount format, it serves as a low-cost alternative to Zener diodes for precise voltage regulation tasks.

Feature Summary

• Programmable output voltage set by two external resistors up to 36 V
• High accuracy with ±1% initial tolerance at room temperature
• Low dynamic output impedance for stable regulation
• AEC-Q101 qualified for automotive reliability standards

Applications

• Shunt regulator circuits
• Precision constant current sinks
• Isolated feedback loops for Switch Mode Power Supplies (SMPS)
• Precision current limiters

Procurement Notes

Verify the specific suffix /8R against official Nexperia documentation to confirm tape-and-reel packaging specifications. Ensure the selected variant matches the required temperature grade and pinning configuration for your PCB layout. Cross-reference the manufacturer part number with authorized distributors to confirm current availability and lead times before finalizing procurement plans.

Selection Notes

Select this component when a ±1% tolerance is required for applications operating between -40°C and 125°C. The SOT-323 package is suitable for space-constrained designs requiring surface-mount technology. Consider the TL431BFDT/8R if tighter ±0.5% accuracy is needed, or the TL431CFDT/8R for standard 2% tolerance requirements at a lower cost point.

Part Context

This part belongs to the TL431 family of three-terminal shunt regulators produced by Nexperia. These devices are widely used as programmable references in power management systems. The AFDT designation specifically indicates the A-grade accuracy level and the SC-70/SOT-323 package type, distinguishing it from other variants like the TO-236AB or DFN packages available in the same series.

Replacement Considerations

Compatible substitutes include the TL431BFDT/8R for higher accuracy and the TL431CFDT/8R for standard tolerance. Other manufacturers' equivalents such as the KA431 or REF43 may be considered if pin compatibility and electrical characteristics align with the design requirements.