What the 5000Vrms isolation and 2.4 µs switching mean for your PLC or motor-drive I/O
The MCT6 is a dual-channel optoisolator in an 8-DIP through-hole package, with a DC input driving a phototransistor output. Its 5000Vrms isolation rating is the headline number for galvanic isolation in industrial environments — it handles the transient overvoltages common on 24 V PLC inputs, motor-drive digital I/O, and sensor feedback lines without breaking down. The 2.4 µs typical turn-on and turn-off time sets the bandwidth ceiling: you can pass 100 kHz digital signals cleanly, but higher-speed protocols like SPI or RS-485 at 1 MHz will see pulse-width distortion. For relay-drive, contact-monitoring, and slow-fieldbus applications, the speed is more than adequate.
CTR floor, output voltage, and current drive — sizing the LED and load resistor
The current transfer ratio has a minimum of 20% at 10 mA forward current. That means with 10 mA through the LED, the output transistor can sink at least 2 mA. The output is rated for 30V maximum and 30 mA continuous per channel. Design the collector resistor so the output transistor does not saturate beyond 400 mV Vce(sat) at the load current — that keeps the logic-level low well within TTL thresholds. Forward voltage is 1.2V typical, and the LED can take up to 60 mA DC forward current. The 400 mV Vce(sat) max is the voltage drop when the output transistor is fully on — at 10 mA load, the drop is well under 0.5 V, which is clean for 5 V logic families.
Active production, ROHS3, and through-hole package availability
It is ROHS3 compliant.
Package and mounting — 8-DIP through-hole for socketed or soldered assembly
The 8-DIP (0.300-inch, 7.62 mm) package is the classic dual-inline footprint. The through-hole mounting allows socketing for prototyping or field replacement.