5300Vrms isolation in a 6-pin SMD
The onsemi CNY17F3SD is a single-channel optoisolator with a transistor output, providing 5300Vrms of galvanic isolation between the DC input and the output side. This isolation rating suits it for separating high-voltage power circuits from low-voltage control logic in industrial and medical equipment where safety isolation is required. The current transfer ratio (CTR) is specified at 100% minimum and 200% maximum, both measured at a forward current of 10 mA. This CTR range means the output transistor can sink at least as much collector current as the LED drive — a 10 mA input yields 10-20 mA output, enough to drive a logic gate or a small relay coil directly.
Quantities are lot-specific and confirmed at RFQ. No pin-compatible drop-in replacement from onsemi has been announced, so a board-level redesign may be required for new production runs.
Temperature range and switching speed
The typical turn-on time is 2 µs and turn-off time is 3 µs, with rise and fall times of 1 µs and 2 µs respectively — fast enough for 100 kHz signal isolation but not for high-speed data links. Maximum output voltage is 70 V, and the output can sink up to 50 mA continuous. Vce saturation is 300 mV max, keeping the on-state voltage drop low when driving logic inputs.
Surface-mount package and tape-and-reel
The CNY17F3SD comes in a 6-pin SMD gull-wing package (6-SMD), supplied on Tape & Reel for automated pick-and-place assembly. The surface-mount footprint saves board space compared to through-hole DIP optoisolators, though the gull-wing leads require a reflow profile compatible with standard lead-free soldering.