The receiver comprises a series of symmetrically-constructed emitter-coupled logic op.amps. (V1-V4) with two complementary outputs. The first stage (V1) works as a transimpedance amplifier in which a suitable voltage is derived from the output current of the photodiode (PD) for amplification by the subsequent stages (V2-V4). To stabilise the operating point of the transimpedance amplifier (V1) its non-negated input is connected via a resistance (R5) to the reference voltage source, and via another resistance (R2) to its negative output. Further negative feedback is provided by a resistor (R3) from the third stage (V3), and by a diode (D) from the second stage (V2), to suppress the offset voltages.
