1N4938

Overview

The Microsemi Corporation 1N4938 is a standard silicon rectifier diode designed for general-purpose switching and computer applications. It features a maximum DC reverse voltage of 175 V and an average forward rectified current of 100 mA. The device operates within a junction temperature range of -65°C to +175°C. Key electrical characteristics include a maximum reverse leakage current of 100 nA at 175 V, a forward voltage drop of 1 V at 100 mA, and a reverse recovery time of 50 ns. It is housed in the DO-204AH (DO-35) axial through-hole package.

Feature Summary

• Standard silicon construction suitable for general-purpose signal and computer diode applications
• High thermal stability with a wide operating junction temperature range extending to 175°C
• Fast switching capability defined by a 50 ns reverse recovery time
• Robust mechanical design utilizing the DO-35 axial leaded package for through-hole mounting

Applications

• General-purpose signal rectification in electronic circuits
• Computer logic interface and switching applications
• Protection against reverse polarity in low-current DC systems
• Clamping and freewheeling functions in small-signal environments

Procurement Notes

Verify the specific manufacturer designation, as Microchip Technology acquired Microsemi assets. Confirm whether the required unit meets military specifications (JAN/JANTX/JANTXV) or commercial grades. Check RoHS compliance status, as many legacy variants are non-compliant. Validate the package type and pin configuration against the target PCB footprint before ordering.

Selection Notes

Select this component when a 175 V reverse voltage rating and 100 mA continuous current capacity are sufficient for the circuit requirements. The 50 ns reverse recovery time makes it appropriate for moderate-speed switching tasks rather than high-frequency RF applications. Ensure the system can accommodate the DO-35 through-hole form factor and that the operating temperature environment remains within the specified -65°C to +175°C junction limits.

Part Context

The 1N4938 belongs to the widely recognized 1N400x series family of standard recovery rectifiers, adapted for lower current ratings compared to the 1A variants. Originally standardized under JEDEC TO-206AD specifications, it serves as a fundamental discrete semiconductor component. Its long-standing availability across multiple manufacturers highlights its role as a staple part in educational, industrial, and consumer electronics designs requiring reliable low-power rectification.