SFH6138

Overview

The SFH6138 is a single-channel optoisolator manufactured by Vishay Semiconductor Opto Division, featuring a Darlington transistor output with an accessible base terminal. It provides high isolation voltage of 5300Vrms and supports surface mount installation in a 4-SMD package. The device operates within a temperature range of -55°C to 100°C and accepts DC input signals. Key electrical characteristics include a maximum collector-emitter saturation voltage of 400mV and a typical forward voltage of 1.4V. The component is currently marked as obsolete.

Feature Summary

• Darlington transistor output configuration with exposed base pin for enhanced control
• High insulation voltage capability ensuring reliable signal isolation
• Surface-mount design suitable for automated PCB assembly processes

Applications

• Industrial automation control systems requiring galvanic isolation
• Power supply feedback loops for voltage regulation
• Microcontroller interface circuits for level shifting and protection

Procurement Notes

Verify the obsolete status of this component before initiating procurement. Confirm availability through authorized distributors or secondary market suppliers. Ensure that any substitute parts meet the required isolation voltage and current transfer ratio specifications. Check RoHS compliance status if environmental regulations apply to your specific application requirements.

Selection Notes

Consider the Darlington output structure which offers higher current gain but slower switching speeds compared to standard transistors. The accessible base allows for external biasing adjustments. Evaluate thermal management needs given the operating temperature range. Compare physical dimensions against available PCB footprint options to ensure mechanical compatibility during integration.

Part Context

This component belongs to the SFH61xx series of optocouplers from Vishay. It shares functional similarities with other devices in the family but differs in package type and specific electrical parameters. The series is designed for general-purpose isolation applications where moderate speed and high gain are prioritized over fast switching performance.

Replacement Considerations

Public confirmed substitutes include the 6N138 from Broadcom Limited. Verify pinout compatibility and electrical parameter alignment before substitution. Ensure the replacement part meets the same isolation voltage and package requirements for direct board-level interchangeability.