The HCPL2731M is a dual-channel optocoupler consisting of an AlGaAs LED optically coupled to a high-gain split darlington photodetector. Its split darlington configuration allows for lower output saturation voltage and higher speed operation than conventional darlington optocouplers. This device features a very low input current requirement of 0.5 mA, a high current transfer ratio of up to 2000%, and an integrated emitter-base resistor for superior stability over temperature. An internal noise shield provides exceptional common mode rejection of 10 kV/µs, making it ideal for applications such as digital logic ground isolation, telephone ring detection, and line receivers for EIA-RS-232C.