The 4N25, 4N26, 4N27 and 4N28 devices consist of a gallium arsenide
infrared emitting diode optically coupled to a monolithic silicon phototransistor
detector.
? Most Economical Optoisolator Choice for Medium Speed, Switching Applications
? Meets or Exceeds All JEDEC Registered Specifications
? To order devices that are tested and marked per VDE 0884 requirements, the
suffix ”V” must be included at end of part number. VDE 0884 is a test option.
Applications
? General Purpose Switching Circuits
? Interfacing and coupling systems of different potentials and impedances
? I/O Interfacing
? Solid State Relays

1. Always design to the specified minimum/maximum electrical limits (where applicable).
2. Current Transfer Ratio (CTR) = IC/IF x 100%.
3. For test circuit setup and waveforms, refer to Figure 11.
4. For this test, Pins 1 and 2 are common, and Pins 4, 5 and 6 are common.