1N5520BUR-1/TR

Overview

The Microchip Technology 1N5520BUR-1/TR is a low voltage avalanche Zener diode with a nominal breakdown voltage of 3.9 V and a ±5% tolerance. It operates within a junction temperature range of -65°C to +175°C and dissipates up to 0.5 W. The device utilizes a hermetically sealed DO-213AA (MELF) surface mount package and features an internal metallurgical bond. Electrical characteristics include a maximum dynamic impedance of 22 Ω at a test current of 20 mA, a forward voltage of 1.1 V at 200 mA, and a maximum reverse leakage current of 1.0 µA at 0.9 V.

Feature Summary

• Hermetically sealed glass MELF package with internal metallurgical bonding for enhanced reliability.
• Qualified per MIL-PRF-19500/437 standards for JAN, JANTX, and JANTXV military levels.
• Inherently radiation hard and nonsensitive to electrostatic discharge.
• Minimal capacitance suitable for high-frequency applications.

Applications

• Voltage regulation over broad operating current and temperature ranges
• Reference voltage sources in precision circuits
• Protection against overvoltage transients

Procurement Notes

Verify the specific ordering suffixes to confirm RoHS compliance status and metallurgical bond inclusion. Ensure the procurement documentation explicitly references the MIL-PRF-19500/437 qualification level required for the application. Confirm that the tape and reel packaging adheres to EIA-481-1-A standards when sourcing bulk quantities.

Selection Notes

Select this component for applications requiring a stable reference voltage in harsh environments due to its radiation hardness and wide thermal operating range. The surface mount MELF package facilitates automated assembly while maintaining hermetic sealing. Verify that the 0.5 W power dissipation rating aligns with the thermal management capabilities of the target printed circuit board layout.

Part Context

This part belongs to the 1N5518BUR-1 through 1N5546BUR-1 series of low voltage avalanche Zener diodes manufactured by Microchip Technology. The series provides a selection of voltages from 3.3 V to 33 V with various tolerance options. These devices are designed to meet rigorous military specifications while offering commercial availability.

Replacement Considerations

Direct substitutes include other parts within the 1N5518B-1 thru 1N5546B-1 axial-leaded series if package adaptation is acceptable. Cross-referencing should focus on matching the 3.9 V nominal voltage, 5% tolerance, and 0.5 W power rating.

FAQ

What does the 'UR' suffix indicate in the part number?

The 'UR' suffix indicates that the device is packaged in a surface mount DO-213AA MELF style package.

How is the polarity identified on the device?

Polarity is indicated by a cathode band; the banded end must be positive with respect to the opposite end for proper Zener regulation operation.