5 kVrms isolation in a 4-DIP — the galvanic gap that keeps noise off the logic side
The TCET1103G is a single-channel phototransistor optocoupler with 5000Vrms isolation. It comes in a 4-DIP through-hole package. Current transfer ratio is 100% minimum and 200% maximum at 10 mA forward current. Output side ratings: 70 V collector-emitter maximum and 50 mA continuous current per channel. The 300 mV Vce(sat) at rated current means minimal voltage drop when the transistor is fully on. The 3 µs rise and 4.7 µs fall times are adequate for 10 kHz to 50 kHz switching — think PWM feedback, relay drivers, or isolated serial data at moderate baud rates. Turn-on and turn-off times are 6 µs and 5 µs respectively.