1N4678

Overview

The Microchip Technology 1N4678 is a 0.5-watt axial-leaded Zener voltage regulator housed in a hermetically sealed glass DO-7 (DO-204AA) package. It provides a nominal Zener voltage of 1.8 V with a standard tolerance of ±5%. The device operates within a temperature range of -65°C to +175°C and features an internal metallurgical bond for high reliability.

Feature Summary

• Hermetically sealed glass axial-lead construction
• Internal metallurgical bond for enhanced reliability
• Inherently radiation hard design
• ESD non-sensitive per MIL-STD-750 Method 1020

Applications

• Voltage regulation over broad operating current ranges
• Reference voltage generation in precision circuits
• Protection against voltage transients

Procurement Notes

Verify the specific manufacturer origin, as the component was originally produced by Microsemi before its acquisition by Microchip Technology. Confirm that the part number corresponds to the commercial grade JEDEC registered version unless military screening prefixes are explicitly required for the application.

Selection Notes

Select this component for applications requiring low-voltage regulation at 1.8 V with strict environmental resilience. Consider the thermal resistance characteristics when mounting on FR4 PCBs, as steady-state power dissipation decreases significantly above ambient temperatures. Ensure lead length meets minimum requirements for accurate electrical characterization.

Part Context

This component belongs to the 1N4678 through 1N4717 series of 0.5-watt Zener diodes. The series covers a voltage selection from 1.8 V to 43 V. The 1N4678 represents the lowest voltage option in this standard axial-leaded lineup, sharing identical mechanical and packaging specifications with higher voltage variants in the same family.

Replacement Considerations

Equivalent surface mount versions are available in the DO-213AA package outline under the 1N4678UR designation. Axial equivalents in the DO-35 glass body package are also offered within the same series.