Quad transistor optocoupler with 3750Vrms isolation
The SFH6916 is a four-channel transistor-output optocoupler in a 16-SOIC surface-mount package, providing 3750Vrms isolation between the DC input side and the transistor output side. It is designed for signal isolation in industrial controls, PLC modules, motor drives, and power-supply feedback paths where multiple isolated channels share a common package.
CTR range and switching — what matters for the BOM
The current transfer ratio spans 50% to 300% at a forward current of 5mA. A 50% minimum CTR means the output transistor can sink at least 2.5mA with 5mA input — enough to drive a TTL or CMOS logic input directly, but check the load current against the 50mA per-channel maximum. The 300% upper bound means the part can saturate with very little LED drive, but the turn-on and turn-off times (5µs and 4µs typical, with 4µs rise and 3µs fall) set the practical switching speed below 100 kHz. For higher data rates, look at a logic-output optocoupler instead.
Output voltage and saturation — rail compatibility
The output transistor is rated for 70V collector-emitter voltage, so it can switch 5V, 12V, 24V, or even 48V logic rails. The 400mV maximum Vce saturation at the rated current keeps the voltage drop low enough for most logic thresholds. With a 50mA per-channel output current, each channel can drive a small relay, an LED indicator, or a logic input directly.
Package and rework — 16-SOIC in a tube
The SFH6916 comes in a 16-SOIC package (0.173" body width, 4.40mm) with a 1.27mm pitch — standard for hand-assembly and rework. The tube shipment keeps the leads straight; no baking required if the moisture-barrier bag is intact.