FOD8173S

Overview

The FOD8173S is a single-channel phototransistor optocoupler manufactured by Fairchild Semiconductor. It features a gallium arsenide infrared LED coupled to an NPN silicon phototransistor in a compact surface-mount package. The device provides high isolation voltage of 5000 Vrms between input and output circuits. Key electrical parameters include a collector-emitter breakdown voltage of 70 V, a maximum forward current of 50 mA, and a typical current transfer ratio of 80%. It operates within a temperature range of -55°C to 110°C.

Feature Summary

• High isolation voltage capability for safe signal transmission across isolated domains
• Compact surface-mount design suitable for automated assembly processes
• Wide operating temperature range ensuring reliability in harsh environments

Applications

• Industrial control systems requiring galvanic isolation
• Signal interfacing between microcontrollers and high-voltage loads
• Power supply feedback loops for voltage regulation

Procurement Notes

Verify the specific suffix designation against the manufacturer's current nomenclature, as part numbers may have transitioned from Fairchild to ON Semiconductor standards. Confirm that the surface-mount package variant matches the required footprint for PCB layout. Ensure compliance with RoHS directives if lead-free construction is mandated for the target application.

Selection Notes

Select this component when a robust, single-channel transistor output optocoupler is needed for general-purpose isolation. Consider the C-speed binning if faster switching speeds are required compared to standard B or D variants. Evaluate the thermal management requirements given the wide operating temperature range and surface-mount power dissipation characteristics.

Part Context

This device belongs to the FOD817 family of optocouplers, which are widely used for isolating digital signals. The '3' suffix typically denotes a specific Current Transfer Ratio (CTR) bin, often corresponding to higher gain than standard variants. The 'S' indicates a surface-mount package configuration, distinguishing it from through-hole DIP versions.

Replacement Considerations

Direct replacements include other FOD817 series variants such as FOD817ASD or FOD817CSD, provided the CTR bin and package type match. Verify pinout compatibility before substitution. Cross-reference with equivalent parts from other manufacturers like HCPL-2630 or PC817, ensuring isolation voltage and package dimensions align.