1N4120 (DO35)

Single Zener Diodes Overview

The Microsemi Corporation 1N4120 is a 30V Zener voltage regulator diode housed in a hermetically sealed glass DO-35 (DO-204AH) axial-lead package. It features an internal metallurgical bond and is rated for a maximum power dissipation of 0.5W at 25°C lead temperature. The device operates within a junction and storage temperature range of -65°C to +175°C, with a thermal resistance of 300°C/W junction-to-ambient. Electrical characteristics include a nominal Zener voltage of 30V measured at a test current of 250µA, a maximum dynamic impedance of 200Ω, and a maximum reverse leakage current of 0.01µA.

Single Zener Diodes Feature Summary

• Internal metallurgical bond construction for enhanced reliability
• Hermetically sealed glass DO-35 axial-lead package
• Qualified per MIL-PRF-19500/435 standards
• Inherently radiation hard design

Single Zener Diodes Applications

• High-reliability voltage regulation circuits
• Military and aerospace electronic systems
• Precision instrumentation reference applications

Single Zener Diodes Procurement Notes

Verify the specific ordering suffix to confirm the required qualification level, as the base JEDEC number corresponds to commercial grade. Confirm RoHS compliance status if environmental regulations apply, noting that e3 suffixes are available on commercial versions only. Ensure the metallurgically bonded variant (-1 suffix) is specified if required by the design. Consult official documentation for tape and reel availability details.

Single Zener Diodes Selection Notes

Select this component when a stable 30V reference is needed in harsh environments requiring radiation hardness. The DO-35 package provides flexible axial-lead mounting suitable for through-hole PCBs. Consider the positive temperature coefficient (+0.095%/°C) for thermal stability requirements. Verify that the operating current remains near the 250µA test point for optimal impedance performance.

Single Zener Diodes Part Context

This part belongs to the 1N4099-1 through 1N4135-1 series of low-noise Zener diodes manufactured by Microsemi. The series offers a wide voltage selection from 1.8V to 100V with various tolerance options. These devices are designed for high-reliability applications where standard commercial components may not suffice, offering robust performance under extreme thermal and electrical stress conditions.

Single Zener Diodes Replacement Considerations

Direct replacements must match the 30V Zener voltage, DO-35 package, and metallurgical bond construction. Equivalent parts should be verified against MIL-PRF-19500/435 specifications for military-grade reliability. Commercial equivalents lacking the -1 suffix or hermetic sealing will not provide identical radiation hardness or long-term stability.