1N6344US/TR

Overview

The Microchip Technology 1N6344US/TR is a surface-mount Zener voltage regulator with a nominal breakdown voltage of 68 V and a maximum power dissipation of 500 mW. It features a standard 5% voltage tolerance and operates within a junction temperature range of -65°C to +175°C. The device utilizes a B-SQ MELF package with voidless hermetically sealed glass construction and internal metallurgical bonds. Electrical characteristics include a dynamic impedance of 155 Ohms at the test current of 1.8 mA, a maximum reverse leakage current of 50 nA at 52 V, and a forward voltage of 1.4 V at 1 A.

Feature Summary

• Hermetically sealed voidless hard glass package with tungsten slugs for robust construction.
• Internal Category I metallurgical bonds ensuring high reliability in critical applications.
• Voltage regulation capability maintained over a broad operating current and temperature range.
• Inherently radiation hard and non-sensitive to electrostatic discharge.

Applications

• High-reliability military and aerospace circuits where failure cannot be tolerated.
• Voltage reference and regulation in harsh environmental conditions.
• Surge protection and transient suppression in sensitive electronic systems.

Procurement Notes

Verify the specific ordering suffix against the manufacturer's part nomenclature guide to confirm voltage tolerance and RoHS compliance status. Ensure the procurement specification matches the required reliability level (JAN, JANTX, JANTXV, or JANS) as commercial versions differ from military-qualified equivalents. Confirm that the B-SQ MELF package dimensions align with the target PCB footprint before finalizing orders.

Selection Notes

Select this component when a surface-mount equivalent to the axial-leaded 1N6309 series is required for space-constrained designs. Consider the 155 Ohm dynamic impedance and 500 mW power rating for thermal management calculations. Verify that the 68 V breakdown voltage meets the circuit requirements and that the -65°C to +175°C operating range covers the intended application environment.

Part Context

This device belongs to the 1N6309US through 1N6355DUS series of 0.5 W glass Zener diodes. It serves as the surface-mount counterpart to the industry-standard axial-leaded components. The series offers extensive voltage selections from 2.4 V to 200 V with various tolerance options, providing a standardized solution for voltage regulation across multiple product lines.

Replacement Considerations

Direct replacements include JAN1N6344CUS/TR and JAN1N6344DUS/TR for tighter voltage tolerances. Axial-leaded equivalents such as 1N6344DUS are functionally compatible but require different mounting methods. Cross-reference MIL-PRF-19500/533 specifications to ensure reliability levels match the original design intent.

FAQ

What type of internal bond does the 1N6344US utilize?

The 1N6344US utilizes an internal Category I metallurgical bond, which is specified for devices in the 1N6321US through 1N6355US range.

Is the 1N6344US package hermetically sealed?

Yes, the device features a voidless hermetically sealed glass package constructed with tungsten slugs to ensure durability and environmental resistance.

How is the polarity indicated on the B-SQ MELF package?

Polarity is indicated by a band on the device body, which marks the cathode terminal.