1N4964

Overview

The Microchip Technology 1N4964 is a military-qualified, voidless hermetically sealed 5-watt glass Zener diode. It provides an 18V nominal Zener voltage with a standard 5% tolerance. The device operates within a junction temperature range of -65°C to +175°C and features a maximum reverse leakage current of 5µA at the specified test voltage. Electrical characteristics include a Zener impedance of 4 Ohms at the test current of 65mA and a positive temperature coefficient of 0.085%/°C. It utilizes axial leads for through-hole mounting.

Feature Summary

• Hermetically sealed voidless-glass construction with internal metallurgical bonds for high reliability
• Military qualification compliant with MIL-PRF-19500/356 standards
• Inherently radiation hard design suitable for harsh environments
• Robust triple-layer passivation resistant to ESD

Applications

• High-reliability aerospace and defense circuits
• Voltage regulation in extreme temperature environments
• Critical power supply reference applications
• Radiation-hardened electronic systems

Procurement Notes

Verify that the specific procurement order explicitly includes the required military qualification suffix (such as JAN, JANTX, or JANS) if compliance with MIL-PRF-19500/356 is mandatory. Standard commercial versions may lack these specific certifications. Confirm package type and lead finish specifications match the design requirements before finalizing orders.

Selection Notes

Select this component for applications requiring robust voltage regulation under severe thermal and environmental stress. The 5W power rating supports significant current handling compared to lower-power variants. Ensure the circuit design accommodates the positive temperature coefficient inherent to the 18V breakdown voltage. Verify that the axial lead form factor fits the available board space and mounting constraints.

Part Context

This part belongs to the 1N4954 through 1N4996 series of 5-watt Zener regulators manufactured by Microsemi's Scottsdale Division. The series offers a wide voltage selection from 3.3V to 390V. These devices are distinguished by their voidless-glass construction and military-grade reliability, making them distinct from standard commercial rectifiers or lower-power Zener diodes.

Replacement Considerations

Direct replacements must match the 5W power dissipation, 18V Zener voltage, and axial lead package. Equivalent parts should also meet MIL-PRF-19500/356 qualifications if the original application requires military-grade certification. Surface-mount equivalents exist but require different footprint considerations.