Active single-channel optoisolator for isolated signal transfer
The MOC212M from onsemi is a single-channel optoisolator with a DC-input LED and a phototransistor output that brings the base terminal out to pin 6. The 2500Vrms isolation rating provides a reinforced barrier between the input and output sides, suitable for separating low-voltage control logic from higher-voltage loads or noisy field wiring. Minimum current transfer ratio of 50% at 10 mA forward current means the output transistor can sink at least 5 mA when the LED is driven at 10 mA — enough to pull a logic input low or drive a small relay directly. The 150 mA continuous output rating and 30 V output breakdown cover typical 24 V PLC input modules and low-power DC loads. Industrial temperature range from -40°C to 100°C allows deployment in outdoor telecom cabinets, motor-drive feedback circuits, and factory-floor isolation without derating. The 8-SOIC package with 3.90 mm body width fits standard surface-mount assembly lines.
Switching speed and saturation for interface design
Turn-on time is 7.5 µs typical, turn-off 5.7 µs typical, with rise and fall times of 3.2 µs and 4.7 µs respectively. These numbers place the MOC212M in the medium-speed class — adequate for 10–100 kHz digital isolation, serial data at 9600 baud, or PWM feedback at a few kHz. For faster edges, a base-emitter resistor can be added to the exposed base pin to speed turn-off at the cost of reduced CTR. Maximum Vce(sat) of 400 mV at the rated forward current keeps the output voltage drop low when the transistor is fully on, minimising power dissipation in the output stage. The forward voltage drop of the input LED is 1.15 V typical, and the absolute maximum DC forward current is 60 mA — the LED should be driven at 10–20 mA for reliable operation over temperature.
Active production with ROHS3 compliance
It is ROHS3 compliant, meeting the latest EU restriction-of-hazardous-substances directive. Sourced per RFQ against your BOM quantity. The 8-SOIC package is a standard industry footprint, and the part is single-sourced from onsemi — no official second-source cross-reference is published.