The Vishay SFH6156-3T is a single-channel optocoupler with a DC input and a phototransistor output, housed in a 4-SMD Gull Wing package for surface-mount assembly. It provides 5300 Vrms galvanic isolation between input and output, making it a standard choice for breaking ground loops in industrial controls, motor drives, and medical equipment where safety isolation is required. The -3T suffix denotes a current transfer ratio (CTR) bin of 100% to 200% at 10 mA forward current — a mid-range gain that suits most logic-level interface designs without overdriving the output.
The 5300 Vrms isolation voltage is the headline safety rating — it covers reinforced insulation requirements per IEC 60950-1 for mains-connected equipment. The transistor output can sink up to 50 mA continuous and block up to 70 V, so it can drive a relay coil, a PLC input, or a 5 V logic gate directly. Vce saturation is 400 mV max, which keeps the on-state voltage drop low enough for 3.3 V logic thresholds. Rise and fall times are 2 µs typical, and turn-on/turn-off times are 3 µs and 2.3 µs — fast enough for 100 kHz switching in isolated gate drive or signal isolation, but not for high-speed data links.
The wide range also suits cold-climate installations and avionics bays that see -40°C starts. Storage temperature extends beyond this range, but the operating limit governs the derating for continuous use.