This application note presents isolation amplifier circuit designs useful in industrial test and measurement systems, instrumentation, and communication systems. It covers the IL300’s coupling specifications, and circuit topologies for photovoltaic and photoconductive amplifier design. Specific designs include unipolar and bipolar responding amplifiers. Both single ended and differential amplifier configurations are discussed. Also included is a brief tutorial on the operation of photodetectors and their characteristics. Galvanic isolation is desirable and often essential in many
measurement systems. Applications requiring galvanic isolation include industrial sensors, medical transducers, and mains powered switchmode power supplies. Operator safety and signal quality are insured with isolated interconnections. These isolated interconnections commonly use isolation amplifiers.