1N4938

Overview

The onsemi 1N4938 is a small signal diode housed in the DO-35 axial package. It features a maximum repetitive reverse voltage of 200 V and an average rectified forward current of 500 mA. The device supports a non-repetitive peak forward surge current of 1.0 A for one-second pulses and 4.0 A for one-microsecond pulses. Electrical characteristics include a maximum forward voltage of 1.0 V at 100 mA, a reverse leakage current of 100 nA at 75 V, and a total capacitance of 5 pF at 0 V bias. The component operates within a junction temperature range up to 175 °C.

Feature Summary

• Provides high-speed switching capabilities with a reverse recovery time of 50 ns.
• Designed for general-purpose applications requiring low forward voltage drop and low leakage current.
• Constructed with epoxy encapsulation classified as UL flammability rating 94V-O.

Applications

• General-purpose rectification in electronic circuits
• Clamping and protection circuits
• Signal processing and computer diode applications

Procurement Notes

Verify that the specific procurement lot matches the manufacturer's current production status, as historical documentation may reference legacy entities like Fairchild Semiconductor. Confirm compliance requirements against the active datasheet revision. Ensure the ordering information aligns with the exact package style and electrical ratings defined in the official specification sheet to avoid functional mismatches.

Selection Notes

Select this component when a standard small-signal diode with a 200 V reverse voltage rating and 500 mA continuous current capacity is required. The DO-35 through-hole package is suitable for standard PCB mounting. Consider the 50 ns reverse recovery time for switching speeds appropriate for general-purpose use rather than high-frequency RF applications.

Part Context

The 1N4938 belongs to the widely recognized 1N49xx series of silicon planar fast-recovery rectifiers. Originally developed by Fairchild Semiconductor, these components are now part of the onsemi portfolio following corporate acquisitions. The series is characterized by its robust mechanical construction and consistent electrical performance across various industrial and commercial environments.

Replacement Considerations

Direct replacements must match the 200 V reverse voltage, 500 mA current rating, and DO-35 package. Verify that substitute parts maintain equivalent reverse recovery times and forward voltage characteristics to ensure circuit compatibility without modification.