Isolation and signal transfer for DC-coupled interfaces
The MOC213M: It is suited for applications where a low-speed digital or analog signal must cross an isolation barrier without ground loops — think PLC digital inputs, motor-drive feedback, or isolated sensor interfaces. The minimum current transfer ratio of 100% at 10 mA forward current means the output transistor can sink at least as much collector current as the LED drive current, giving predictable gain for logic-level translation or relay drive. The 150 mA continuous output rating and 30 V output compliance handle small solenoids, indicator lamps, or downstream logic gates directly.
Switching speed and timing margins
Typical turn-on time is 7.5 µs and turn-off is 5.7 µs, with rise/fall times of 3.2 µs and 4.7 µs respectively. This places the MOC213M in the medium-speed class — adequate for 10–100 kHz switching in industrial control loops, but not for high-speed serial isolation. The base terminal is brought out, so the designer can add a speed-up resistor between base and emitter to reduce turn-off time at the cost of some CTR.
Package, mounting, and board-fit
Housed in an 8-SOIC surface-mount package (3.90 mm body width, 0.154" pitch), the MOC213M fits standard SOIC-8 footprints. The supplier device package is listed as 8-SOIC, and the part ships in tubes — not tape-and-reel, so plan for tube-to-reel transfer if the pick-and-place line expects reels.