1N4966US

Overview

The Microchip Technology 1N4966US is a surface mount Zener voltage regulator with a nominal breakdown voltage of 22 V. It operates at a test current of 50 mA and features a maximum dynamic impedance of 5.0 Ohms at this point, rising to 1.8 Ohms at a knee current of 1 mA. The device dissipates up to 5 Watts at an ambient temperature of 140°C and withstands surge currents of 7.0 Amps for 8.3 ms square waves. It exhibits a voltage temperature coefficient of +0.085 %/°C and maintains a maximum reverse leakage current of 2 µA.

Feature Summary

• Hermetically sealed voidless glass construction with internal metallurgical bonds
• Military qualified to MIL-PRF-19500/356 standards
• Robust design inherently resistant to electrostatic discharge

Applications

• High-reliability aerospace systems
• Defense electronics requiring radiation hardness
• Critical power supply regulation circuits

Procurement Notes

Verify the specific revision level against the latest Microsemi datasheet SD44A before procurement. Confirm that the ordering suffix matches the required tolerance class, as standard parts lack additional letters. Ensure compliance with RoHS exemptions if applicable, as indicated in manufacturer documentation. Validate package marking absence and polarity band orientation during incoming inspection.

Selection Notes

Select this component when high thermal stability and hermetic sealing are mandatory. The 5W rating supports significant power dissipation in compact surface mount footprints. Consider the positive temperature coefficient for applications where voltage rise with heat is acceptable or manageable within circuit design parameters.

Part Context

This part belongs to the 1N4954US through 1N4996US series of 5-watt Zener regulators. These devices share identical mechanical dimensions and mounting characteristics. They utilize the E package, also known as D-5B, which facilitates automated surface mount assembly while maintaining military-grade reliability standards.

Replacement Considerations

Direct replacements include other 1N49xxUS series variants from Microchip Technology provided the voltage rating matches exactly. Equivalent axial-leaded versions exist by removing the US suffix, though mechanical mounting differs.