MCT2E is a phototransistor Optocoupler, as the name “phototransistor” suggests it has a transistor that is controlled based on light (photon). So this IC basically has an IR (infrared) LED and a photo-transistor inside it. When the IR led is powered the light from it falls on the transistor and it conducts. The arrangement and pin-outs of the IR LED and the photo-transistor is shown below.
This IC is used to provide electrical isolation between two circuits, one part of the circuit is connected to the IR LED and the other to Photo-transistor. The digital signal given to the IR LED will be reflected on the transistor but there will be no hard electrical connection between the two. This comes in very handy when you are trying to isolate a noisy signal from your digital electronics, so if you are looking for an IC to provide optical isolation in your circuit design then this IC might be the right choice for you.
Input Diode Forward Voltage: 1.25V
Collector-Emitter Voltage: 30V
On-State Collector Current: 5mA
Transistor HFE: 300
Rise Time: 5us
Fall Time: 5us
Available as 6-pin PDIP with and without M-suffix