The ILD621/ ILQ621 and ILD621GB/ ILQ621GB are multi-channel phototransistor optocouplers that use GaAs IRLED emitters and high gain NPN silicon phototransistors. These devices are constructed using double molded insulation technology. This assembly process offers a withstand test voltage of 7500 VDC. The ILD621/ ILQ621GB is well suited for CMOS interfacing given the CTR CE sat of 30 % minimum at I F of 1.0 mA. High gain linear operation is guaranteed by a minimum CTR CE of 100 % at 5.0 mA. The ILD/Q621 has a guaranteed CTR CE 50 % minimum at 5.0 mA. The TRansparent IOn Shield insures stable DC gain in applications such as power supply feedback circuits, where constant DC VIO voltages are present.