ELECTRIC CURRENT SUPPRESSING MODULATION CIRCUIT FOR SEMICONDUCTOR OPTICAL DEVICE

摘要

An electric current suppressing modulation circuit for a semiconductor optical device is provided to maximize light-emitting efficiency by realizing low power consumption, low heating, and high efficiency through electric current suppressing modulation. An electric current suppressing modulation circuit for a semiconductor optical device includes an integrator(210), a detector(220), a control signal generating unit(230), and a tracking circuit(240). The integrator(210) integrates a power voltage, which is a system output signal, and generates a signal of an integral waveform of turn-on time longer than the turn-on time of the power voltage. The detector(220) detects the level of the signal of the integral waveform generated by the integrator(210). The control signal generating unit(230) generates a tracking control signal according to the level of the signal of the integral waveform detected by the detector(220). The tracking circuit(240) performs a tracking operation of instantaneously repeating on and off for the signal of the integral waveform inputted from the integrator(210) according to the tracking control signal from the control signal generating unit(230), and outputs a predetermined suppressing current modulation signal for operating the optical device.