1N5518BUR-1

Overview

The Microchip Technology 1N5518BUR-1 is a low voltage avalanche Zener diode with a nominal breakdown voltage of 3.3 V at a test current of 20 mA. It operates within a junction temperature range of -65 °C to +175 °C and dissipates up to 0.5 W. The device features a hermetically sealed DO-213AA MELF surface mount package with an internal metallurgical bond. It is qualified per MIL-PRF-19500/437 for JAN, JANTX, and JANTXV reliability levels.

Feature Summary

• Hermetically sealed glass MELF package with internal metallurgical bond
• Qualified per MIL-PRF-19500/437 for JAN, JANTX, and JANTXV levels
• Inherently radiation hard design
• ESD nonsensitive per MIL-STD-750 Method 1020

Applications

• Voltage regulation in aerospace avionics systems
• Data acquisition and control circuits for spacecraft
• High-reliability military electronic assemblies

Procurement Notes

Verify the specific ordering suffix against the manufacturer's nomenclature guide to confirm tolerance and RoHS status. Ensure the procurement specification explicitly requires the metallurgical bond construction (-1) and the correct military qualification level (JAN, JANTX, or JANTXV). Confirm that the supplier provides traceability documentation required for space-grade components.

Selection Notes

Select this component when a surface mount equivalent to the axial 1N5518 is required for high-reliability applications. The metallurgical bond option ensures structural integrity under thermal cycling. Verify that the 3.3 V nominal voltage aligns with the circuit requirements and that the 0.5 W power rating accommodates the maximum operating current without exceeding thermal limits.

Part Context

This part belongs to the 1N5518BUR-1 through 1N5546BUR-1 series of 0.5 W glass surface mount Zener regulators. The series covers voltages from 3.3 V to 33 V. These devices serve as surface mount replacements for the JEDEC registered 1N5518 through 1N5546 axial-leaded series, maintaining similar electrical characteristics in a compact MELF form factor.

Replacement Considerations

Direct replacement options include the standard commercial versions 1N5518B or 1N5518 if military qualification is not required. For axial leaded equivalents, the 1N5518B-1 offers the same metallurgical bond but in a DO-35 package.