Isocom sfh615a series optoisolators 1 channel low input current 4 pin isocom sfh615a 3x an optically coupled isolator with a current transfer ratio of 100 to 200 consists of an ir led and a npn silicon photodiode in a space efficient 4 pin package low input current and high current transfer ratio make these photocouplers suitable for a range of applications such as computer terminals industrial systems controllers measuring instruments etc isocom sfh615a 3x optoisolator 1 channel 100 2