Isolation rating and CTR window
The TLP182(Y,E provides 3750Vrms isolation between input and output for galvanic isolation in industrial interfaces, PLC digital inputs, and AC-mains sensing circuits. Current transfer ratio spans 50% to 150% at a forward current of 5 mA — the 3:1 spread means the load resistor on the transistor output must be sized for the minimum CTR to guarantee saturation, while the maximum CTR caps the switching speed because the phototransistor takes longer to turn off with higher base drive.
AC/DC input and switching timing
The input accepts both AC and DC signals — two back-to-back LEDs inside the package let this part handle rectified AC waveforms or DC logic levels without an external bridge, saving board space on a phase-detection or zero-crossing input stage. Typical turn-on and turn-off times are 3 µs each, with rise/fall of 2 µs and 3 µs — the 80V output rating and 50 mA continuous output current suit it for driving a downstream logic gate or a small relay coil.