5000Vrms isolation in a 4-DIP through-hole package
The Vishay TCET1109 is a single-channel transistor-output optocoupler in a 4-DIP (0.300", 7.62mm) through-hole package, rated for 5000Vrms isolation. It accepts a DC input and drives a phototransistor output capable of 50mA continuous current and 70V across the output. The current transfer ratio (CTR) is specified at 200% minimum and 400% maximum when the forward diode is driven at 5mA, giving a wide gain window for logic-level or relay-drive interfaces.
CTR range and switching timing
With CTR guaranteed between 200% and 400% at 5mA forward current, the TCET1109 provides a predictable transfer ratio that simplifies worst-case design for both minimum-drive and saturation-margin calculations. The typical turn-on time is 6µs and turn-off time 5µs, with rise and fall times of 3µs and 4.7µs respectively — fast enough for 10–20 kHz switching in isolated gate drives or status feedback loops. Vce saturation is limited to 300mV, keeping output voltage drop low when the transistor is fully on.
