1N2805A

Overview

The Microchip Technology 1N2805A is a silicon unidirectional voltage regulator diode designed for high-power applications. It features a nominal Zener voltage of 7.5 V with a tolerance of ±10%. The device supports a maximum power dissipation of 50 W and operates within a temperature range of -65°C to 175°C. It utilizes the TO-204AD (TO-3) through-hole package, which includes a tab for mounting. Key electrical characteristics include a reverse leakage current of 100 µA at 5 V and a forward voltage of 1.5 V at 10 A. The dynamic impedance is specified at a maximum of 0.3 Ohms.

Feature Summary

• High power handling capability of 50 W for robust voltage regulation
• Wide operating temperature range suitable for extreme environments
• Hermetically sealed construction in a metal TO-3 package

Applications

• Military and aerospace electronic systems requiring radiation-hardened or high-reliability components
• Industrial power supply voltage regulation circuits
• Protection circuits in harsh environmental conditions

Procurement Notes

Verify that the specific order suffix matches the required tolerance level, as variants such as 1N2805B and 1N2805C offer tighter tolerances than the standard ±10% of the base model. Confirm hermetic sealing requirements if the application demands it, as some commercial equivalents may not be sealed. Ensure the manufacturer source is authorized, given the component's history across multiple entities including Microsemi and Motorola. Check for RoHS compliance status, as this specific part number is often classified under EAR99 and may not meet modern environmental directives.

Selection Notes

Select the 1N2805A when a nominal 7.5 V regulation point with moderate precision is sufficient. Consider alternative suffixes like 1N2805B (±5%) or 1N2805C (±2%) if stricter voltage accuracy is required. The TO-3 package necessitates adequate thermal management solutions due to the 50 W power rating. Verify that the through-hole mounting style fits the PCB design constraints compared to surface-mount alternatives.

Part Context

This component belongs to the 1N2805 series of 50 Watt Zener Diodes originally developed by Microsemi Corporation. The series includes various tolerance grades denoted by suffix letters. The 1N2805A specifically represents the standard tolerance variant. The technology has been maintained through corporate transitions, with Microchip Technology currently listing the part. It serves as a legacy high-power discrete semiconductor solution.

Replacement Considerations

Publicly confirmed substitute part numbers include 1N2805B and 1N2805RB from Microchip Technology. These variants share the same package and basic power ratings but differ in voltage tolerance specifications.