1N4978US

Single Zener Diodes Overview

The Microchip Technology 1N4978US is a surface mount Zener voltage regulator with a nominal breakdown voltage of 68 V and a maximum power dissipation of 5 W. It features a standard voltage tolerance of ±5% and operates within a junction temperature range of -65°C to +175°C. The device exhibits a maximum dynamic impedance of 50 Ohms at the test current (IZT) of 20 mA, with a reverse leakage current of 2 µA at 51.7 V. Forward voltage is specified as 1.5 V at 1 A.

Single Zener Diodes Feature Summary

• Hermetically sealed voidless glass construction for high-reliability applications
• Military qualification per MIL-PRF-19500/356
• Internal metallurgical bonds for enhanced robustness
• Inherently radiation hard

Single Zener Diodes Applications

• High-reliability military systems
• Spacecraft electronics
• Avionics circuits
• Harsh environment voltage regulation

Single Zener Diodes Procurement Notes

Verify that the component meets specific military qualification requirements under MIL-PRF-19500/356. Confirm the package type matches the D-5B outline and ensure compatibility with lead-free or tin/lead termination finishes depending on assembly constraints. Check for RoHS compliance status as these devices are typically non-compliant.

Single Zener Diodes Selection Notes

Select this component when a 68 V regulation point is required in a surface mount configuration. Ensure the thermal design accommodates the 5 W power rating and derating curves up to 175°C. Verify that the 50 Ohm dynamic impedance meets circuit stability requirements.

Single Zener Diodes Part Context

This part belongs to the 1N4954US through 1N4996US series of 5 Watt Zener Voltage Regulators. These components are designed for applications where failure cannot be tolerated, offering extensive voltage selections from 3.3 to 390 volts in standard 5% tolerances.

Single Zener Diodes Replacement Considerations

JAN1N4978

Single Zener Diodes FAQ

What is the maximum operating junction temperature?

The maximum operating junction temperature is +175°C.

Is the package hermetically sealed?

Yes, the 1N4978US features a voidless hermetically sealed glass package.