1N4965

Overview

The Microchip Technology 1N4965 is a military-qualified, voidless hermetically sealed glass Zener diode rated for 5 watts of power dissipation. It features a nominal Zener voltage of 20 V with a standard tolerance of ±5%. The device operates within a temperature range of -65°C to +175°C and utilizes an axial lead 'E' package. Key electrical characteristics include a maximum Zener impedance of 4.5 Ohms at the test current (IZT) of 65 mA, a maximum reverse leakage current of 2 µA at 15.2 V, and a forward voltage of 1.5 V at 1 A.

Feature Summary

• Hermetically sealed construction using voidless hard glass with tungsten slugs and internal metallurgical bonds for extreme robustness.
• Military qualification compliant with MIL-PRF-19500/356, ensuring high reliability for critical applications.
• Inherently radiation hard and non-sensitive to electrostatic discharge (ESD).
• Triple-layer passivation provides enhanced protection against environmental stress.

Applications

• High-reliability aerospace and defense systems where failure cannot be tolerated.
• Voltage regulation circuits requiring broad operating current and temperature stability.
• Harsh environment electronics utilizing extended temperature performance capabilities.

Procurement Notes

Verify that the specific ordering suffix matches the required military grade (e.g., JAN, JANTX, JANS) as these designations dictate the exact screening and testing levels per MIL-PRF-19500/356. Confirm package type requirements, noting that surface-mount equivalents exist with a US suffix. Ensure compliance with RoHS status if applicable to the specific variant, as some military grades may not meet standard environmental directives.

Selection Notes

Select the 1N4965 when a 20 V reference is needed in a high-power 5 W axial configuration. Consider the 4.5 Ohm dynamic impedance for load regulation requirements. Evaluate the thermal resistance of 22 °C/W for heat sinking needs. Compare against lower power variants if system constraints allow, or higher voltage siblings within the 1N4954–1N4996 series for different regulation points.

Part Context

This component belongs to the industry-recognized 1N4954 through 1N4996 series of 5 Watt Zener Voltage Regulators manufactured by Microsemi (now Microchip Technology). The series offers extensive voltage selections from 3.3 V to 390 V. These devices are designed for applications demanding superior durability and long-term stability under severe operational conditions.

Replacement Considerations

Surface-mount equivalents are available in square end-cap MELF packages identified by the US suffix (e.g., 1N4965US). Other manufacturers produce JEDEC registered equivalents, but verification of MIL-PRF-19500/356 compliance is necessary for direct military-grade substitution.

FAQ

What is the maximum continuous regulator current for the 1N4965?

The maximum continuous regulator current (IZM) is 237 mA.

How does the 1N4965 handle electrostatic discharge?

The device is inherently non-sensitive to electrostatic discharge (ESD) per MIL-STD-750 Method 1020.