This circuit is suggested by Motorola and makes use of a phototransistor with its own encapsulation for connection in plastic optical fibers of 1,000 microns. Using an MFOE76 as a transmitter, this detector allows the use of optical fibers up to 100 meters in length in the transmission of TTL data. The supply is 5 V and the circuit uses one of the 4 triggers available in a 74L8132. The recommended operating frequency for the circuit is 7.5 kHz.
