Isolation voltage and CTR — the two specs that decide fit
The SFH6106-4 is a Vishay single-channel optocoupler with a DC-input phototransistor output, rated for 5300Vrms isolation. That isolation level supports reinforced insulation in mains-connected power supplies, motor drives, and industrial PLC I/O modules where safety isolation is required. The current transfer ratio is specified as a minimum of 160% and a maximum of 320% at a forward current of 10 mA — a tight bin that gives the designer a predictable LED drive current and logic-level output swing across the full -55°C to 100°C operating range.
Switching speed and output drive
This places the SFH6106-4 in the general-purpose speed class — adequate for 50/60 Hz line synchronization, relay drivers, and digital input sampling at low kHz rates, but not for high-speed serial isolation. The transistor output can sink up to 50 mA and block up to 70 V, with a Vce saturation maximum of 400 mV at the rated current, keeping power dissipation low in the on-state.
Housed in a 4-SMD Gull Wing package (supplier device package 4-SMD), this part is designed for surface-mount assembly. The Gull Wing leads provide good coplanarity for automated pick-and-place and visual solder-joint inspection. The Tube shipping medium means the parts arrive in a rigid anti-static tube — verify your feeder setup accepts Tube-fed components or plan a transfer to tape-and-reel if your line is reel-only.
The wide temperature range and isolation rating make it a stable choice for industrial and automotive-grade BOMs.