3750Vrms isolation in a 4-SMD Gull Wing
The SFH690AT3 is a single-channel Vishay optocoupler with a phototransistor output, delivering 3750Vrms of galvanic isolation between input and output sides. Packaged in a 4-SMD Gull Wing (4-SOP with 2.54mm pitch), it's designed for surface-mount assembly on mixed-signal boards where ground loops or voltage differentials need breaking. With a DC input and a current transfer ratio (CTR) specified between 50% and 150% at a forward current of 5mA, this part gives a predictable current gain window for driving logic-level inputs or low-power loads up to 50mA per channel.
Switching speed and drive capability
Typical rise and fall times are 3µs and 4µs respectively, with turn-on and turn-off times of 5µs and 3µs. This positions the SFH690AT3 for moderate-speed signal isolation — think PLC digital inputs, relay drivers, or DC bus voltage sensing where microsecond-level response is sufficient. The output transistor can handle up to 70V across the collector-emitter, with a saturation voltage of 300mV max at rated current. This 70V ceiling covers 24V and 48V industrial rails with margin, while the low Vce(sat) keeps power dissipation minimal in the on-state.
Temperature range and compliance
No official successor or second-source cross-reference is recorded — this is a sole-sourced BOM line from Vishay.