The FOD2743 Optically Isolated Amplifier consists of the popular KA431 percision programmable shunt reference and an optocoupler. The optocoupler is a gallium arsenide (GaAs) light emitting diode optically coupled to a silicon phototransistor. It comes in 3 grades of reference voltage tolerance = 2%, 1% and 0.5%.The Current Transfer Ratio, (CTR) ranges from 50% to 100%. It also has an outstanding temperature coefficient of 50 ppm/°C. It is primarily intended for use as the error amplifier/reference voltage/optocoupler function in isolated ac to dc power supplies and dc/dc converters.When using the FOD2743, power supply designers can reduce the component count and save space in tightly packaged designs. The tight tolerance eliminates the need for adjustments in many applications. The device comes in an 8-pin dip white package.