1N4938

Overview

The Fairchild Semiconductor 1N4938 is a silicon polarity switching diode designed for high-speed computer and general-purpose applications. It features a continuous average forward rectified current of 500 mA and a maximum repetitive peak reverse voltage of 200 V. The device exhibits a typical forward voltage drop of 1 V at 500 mA and a maximum reverse leakage current of 100 nA at 200 V. Its junction temperature range spans from -65°C to +175°C, ensuring reliable operation in demanding environments.

Feature Summary

• High-speed silicon switching capability optimized for computer logic circuits
• Robust thermal performance with extended junction temperature range
• Standard DO-35 axial leaded package for through-hole mounting

Applications

• Computer logic circuit protection
• General-purpose rectification
• Polarity switching applications

Procurement Notes

Verify the specific manufacturer source, as the 1N4938 is produced by multiple vendors including Fairchild, Microchip, and NTE Electronics. Confirm that the component matches the required 200V rating and 500mA current capacity. Check for RoHS compliance status if environmental regulations apply to your assembly process. Ensure the package type aligns with your PCB footprint requirements.

Selection Notes

Select this component when a standard small-signal diode with 200V reverse voltage and 500mA forward current is required. It serves as a direct replacement for other 1N49xx series diodes with similar ratings. Consider the DO-35 package size for board space constraints. Verify the reverse recovery time specifications if high-frequency switching is involved in the design.

Part Context

The 1N4938 belongs to the widely used 1N49xx series of general-purpose silicon rectifiers. These components are standardized across various manufacturers to ensure interchangeability. The series typically offers consistent electrical characteristics for low-power switching tasks. This part number represents a specific voltage and current rating within that broader family of discrete semiconductor devices.

Replacement Considerations

The 1N4938-1 is a documented variant available from Microchip. Other equivalents may include parts from NTE Electronics or New Jersey Semi-Conductor. Verify pinout compatibility and thermal dissipation capabilities before substituting.