Patent ID: 8098059
Filing Date: 2012-01-17
Classification: H02M

Abstract:
1. A current negative-feedback circuit comprising a sawtooth-shaped waveform generation means for generating a sawtooth-shaped waveform and inputting it into a PWM comparator provided for a control means for storing energy in an inductance by switching a switching device on/off and controlling a series of converter sequences discharging the energy to a load, said circuit comprising current detection means for detecting a charge current of the inductance, wherein said current detection means comprises a current mirror circuit for outputting a current proportional to the charge current of the inductance via the switching device or for outputting a current which is a quadratic function of the charge current of the inductance, said sawtooth-shaped waveform generation means comprises an oscillator, a constant-current source, first and second MOSFETs which are complementary, and charge/discharge means provided with a capacitor, so as to discharge the capacitor or charge it with constant current by complementarily switching the first and second MOSFETs on/off according to an oscillation output of the oscillator and said sawtooth-shaped waveform generation means adds constant charge current of the charge/discharge means and current output from the current mirror circuit, charges the capacitor, and generates a sawtooth-shaped waveform.