1N6344

Overview

The Microchip Technology 1N6344 is a military-qualified Zener voltage regulator featuring a 68 V nominal breakdown voltage with a standard ±5% tolerance. It operates within a -65 °C to +175 °C junction temperature range and dissipates up to 0.5 W of steady-state power. The device exhibits a dynamic impedance of 155 ohms at the 1.8 mA test current, with a maximum reverse leakage current of 50 µA at 150 °C. It utilizes a voidless hermetically sealed glass package available in DO-35 axial-lead or SQ MELF surface-mount configurations.

Feature Summary

• Hermetically sealed construction using voidless hard glass with tungsten slugs for high-reliability environments.
• Military qualification per MIL-PRF-19500/533 across JAN, JANTX, JANTXV, and JANS reliability levels.
• Inherently radiation-hardened design suitable for aerospace and defense applications.
• Robust metallurgical bonds ensuring resistance to ESD and mechanical stress.

Applications

• High-reliability aerospace and defense circuits
• Space-grade electronic systems requiring radiation hardness
• Critical military equipment where failure is not tolerated
• Voltage regulation in extreme temperature environments

Procurement Notes

Verify the specific suffix (e.g., DUS/TR) to confirm the exact package type and reel configuration. Confirm whether the required lot requires JAN, JANTX, JANTXV, or JANS qualification levels. Ensure compliance with RoHS requirements if applicable, as commercial versions differ from military grades. Check for lead finish specifications regarding tin/lead versus matte/tin options based on assembly constraints.

Selection Notes

Select this component when a 68 V reference is needed in harsh environments. Consider the SQ MELF package for surface-mount designs requiring compact footprints. Evaluate thermal derating curves for operation above 75 °C lead temperature. Verify that the 155 ohm dynamic impedance meets the noise and stability requirements of the target circuit design.

Part Context

This part belongs to the 1N6309 through 1N6355D series of 500 mW Zener diodes. The series covers a wide voltage range from 2.4 V to 200 V. All devices share identical physical packaging and qualification standards, differing primarily in their nominal breakdown voltage and associated electrical characteristics such as test current and dynamic impedance.

Replacement Considerations

Direct substitutes include other 1N6344 variants with different suffixes indicating package or tolerance changes, such as 1N6344CUS or 1N6344DUS. Cross-brand replacements must match the 68 V rating, 0.5 W power dissipation, and hermetic sealing requirements to maintain system reliability.