Optical receiving circuit

• Main Author: TAKIBA YUKIKO
• Format: Patent
• Language: English
• Published: 23.06.2015
• Subjects: AMPLIFIERS; BASIC ELECTRONIC CIRCUITRY; ELECTRIC COMMUNICATION TECHNIQUE; ELECTRICITY; TRANSMISSION

Provided is an optical receiving circuit that reduces a distortion of an output pulse width with respect to an input signal by adjusting the division ratio for a voltage applied to resistors in a resistor network. The optical receiving circuit includes: a differential amplifier 2 that converts a current signal converted from an optical input L and outputs a non-inverting voltage V+ and an inverting voltage V− whose amplitudes are regulated; a peak detector 5 that detects a peak voltage Vp of the non-inverting voltage V+ and outputs the peak voltage Vp; a resistor network 4 performing a summation operation based on the peak voltage Vp, the non-inverting voltage V+, and the inverting voltage V− to thereby generate a non-inverting input voltage V1+ and an inverting input voltage V1− whose oscillations cross each other at the middle points of the amplitudes thereof; a discriminator 3 that discriminates a potential at which the oscillations of the non-inverting input voltage V1+ and the inverting input voltage V1− cross each other, and generates a rectangular signal in accordance with the cross potential; and an adjustment circuit 6 that, when the non-inverting voltage V+ or the inverting voltage V− is outputted with the amplitude thereof regulated in the differential circuit, adjusts a relative ratio between the voltages connected respectively to resistors of the resistor network 4, in such a way that the rectangular signal is outputted in the same waveform as the optical input L.