1N6349US

Overview

The Microchip Technology 1N6349US is a military-qualified Zener voltage regulator with a nominal breakdown voltage of 110 V. It operates within a junction temperature range of -65 °C to +175 °C and dissipates up to 0.5 W at an end cap temperature of 150 °C. The device features a maximum reverse leakage current of 80 µA at 25 °C and 100 µA at 150 °C, with a dynamic impedance of 500 Ω at the test current of 1.1 mA. It utilizes a voidless hermetically sealed glass MELF package.

Feature Summary

• Hermetically sealed voidless hard glass construction with tungsten slugs for high-reliability environments
• Qualified per MIL-PRF-19500/533 for JAN, JANTX, JANTXV, and JANS reliability levels
• Inherently radiation hard and non-sensitive to electrostatic discharge
• Internal metallurgical bonds ensuring robust mechanical integrity

Applications

• High-reliability aerospace systems where failure cannot be tolerated
• Military-grade electronic circuits requiring strict environmental resilience
• Voltage regulation in harsh operating conditions across broad temperature ranges

Procurement Notes

Verify that the specific order matches the required reliability level (JAN, JANTX, JANTXV, or JANS) as indicated by the part nomenclature. Confirm RoHS compliance status if applicable, noting that compliant versions are available on commercial grade only. Ensure the procurement documentation references the correct JEDEC type number and tolerance specifications.

Selection Notes

Select this component when a surface mount equivalent to the axial-leaded 1N63xx series is required for space-constrained designs. Consider the 110 V nominal voltage and 500 Ω dynamic impedance for precise regulation needs. Evaluate the thermal resistance characteristics against the expected power dissipation and ambient temperature constraints of the target application.

Part Context

This device belongs to the 1N6309US through 1N6355DUS series of 0.5 W Zener voltage regulators. It serves as the surface mount B-SQ MELF package counterpart to the industry-standard axial-leaded components. The series provides extensive voltage selections from 2.4 V to 200 V with standard and tight tolerances.

Replacement Considerations

Direct replacements include other manufacturers' equivalents of the 1N6349JEDEC type number. Verify that substitute components meet the same MIL-PRF-19500/533 qualification standards and maintain identical MELF package dimensions for board compatibility.

FAQ

What is the maximum surge current rating for the 1N6349US?

The maximum non-repetitive peak Zener surge current (IZSM) for the 1N6349US is 84 Amps under an 8.3 ms square wave condition.

How does the package polarity indicate the cathode?

Polarity is indicated by a band on the end cap of the MELF package, identifying the cathode terminal.