The FOD2200 is an optically coupled logic gate that combines an AlGaAs LED and an integrated high gain photo detector. The detector has a three state output stage and has a detector threshold with hysteresis. The three state output eliminates the need for a pullup resis- tor and allows for direct drive of data busses. The hyster- esis provides differential mode noise immunity and eliminates the potential for output signal chatter. The Electrical and Switching Characteristics of the FOD2200 are guaranteed over the temperature range of 0°C to 85°C and a VCC range of 4.5V to 20V.