The ILD620/ ILQ620 and ILD620GB/ ILQ620GB are multi-channel input phototransistor optocouplers that use inverse parallel GaAs IRLED emitter and high gain NPN silicon phototransistors per channel. These devices are constructed using over/under leadframe optical coupling and double molded insulation resulting in a withstand test voltage of 5300 VRMS. The LED parameters and the linear CTR characteristics make these devices well suited for AC voltage detection. the ILD/Q620GB with its low IF quaranteed CTRCEsat minimizes power dissipation of the AC voltage detection network that is placed in series with the LEDs. Eliminating the phototransistor base connection provides added electrical noise immunity from the transients found in many industrial control environments.