1N4956

Overview

The Microchip Technology 1N4956 is a military-qualified, voidless hermetically sealed glass Zener diode rated for 5 watts of power dissipation. It features an axial lead 'E' package and operates within a temperature range of -65°C to +175°C. The nominal Zener voltage is 8.2 V with a standard tolerance of ±5%. Key electrical characteristics include a test current (IZT) of 150 mA, a maximum reverse leakage current of 50 µA at 6.2 V, and a dynamic impedance (ZZT) of 1.5 Ω.

Feature Summary

• Military qualification compliant with MIL-PRF-19500/356 standards
• Voidless hermetically sealed glass construction with internal metallurgical bonds
• Inherently radiation hard and non-sensitive to electrostatic discharge

Applications

• High-reliability aerospace systems
• Defense electronics requiring failure-intolerant components
• Harsh environment voltage regulation circuits

Procurement Notes

Verify the specific revision level and manufacturing origin when sourcing this component. Confirm that the ordering suffix matches the required tolerance or package variant, as these details define the exact electrical specifications. Ensure compliance with the applicable military specification requirements for your intended deployment environment.

Selection Notes

Select the 1N4956 for applications demanding high thermal stability and robust physical construction in extreme conditions. The device supports a broad operating temperature range and offers flexible axial-lead mounting. Consider the available surface-mount equivalents if space constraints require a different form factor while maintaining similar performance profiles.

Part Context

This component belongs to the industry-recognized 1N4954 through 1N4996 series of 5-watt Zener voltage regulators. Manufactured by Microsemi's Scottsdale Division, the series provides extensive voltage selections from 3.3 to 390 volts. These devices are designed for critical applications where long-term reliability and resistance to environmental stressors are paramount.

Replacement Considerations

Surface-mount equivalents are available in square end-cap MELF configurations with the 'US' suffix, such as the 1N4956US.