An optical receiver IC for fiber-optic data links has been developed for use in multiplex wiring harnesses. This IC consists of a PD (Photodiode), a transimpedance, an amplifier, and a comparator to be compatible with TTL. A PD and these circuits are all integrated into one chip, the size of which is 3 mm square, by using the Si-bipolar process. It is hermetically sealed in a can package. It operates at a data rate up to 1 Mbps (Mbps = 106 bits per second). It also has no requirement of sensitivity adjustment for its wide dynamic range (25 dB).