The FOD2742 Optically Isolated Amplifier consists of the popular KA431 precision 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 100% to 200%. 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. FUNCTIONAL BLOCK DIAGRAM