- SYNCHRONOUS DC-DC BUCK CONVERTER FOR REDUCING ELECTROMAGNETIC INTERFERENCE USING DIGITAL DELAY LOCKED LOOP AND METHOD FOR CONTROLLING SHAPING OF SWITCHING SIGNALS

摘要

synchronous direct current in accordance with embodiments of the present invention - DC buck converter includes a first switch which is applied to the inductor to the input voltage during the duty (duty) period of the first switching signal, the first switching the synchronous direct current to generate an output voltage step-down by using the second switch is switched to the complementary second switching signal to the signal as a DC buck converter, a sawtooth wave generation unit generating a sawtooth wave with a frequency according to the frequency reference signal, the output voltage and generating an error voltage of the reference voltage and the sawtooth wave and the drive oscillator signal generating unit compares the error voltage to generate a drive oscillator signal having a duty ratio corresponding to the magnitude of the error voltage, applying the dead time to the duty interval of the drive oscillator signal a switching signal generation unit and the drive oscillator signal and the reference frequency variation signal in accordance with the active period of the pulse length of the spread spectrum on the signal clock setting voltage corresponding to the phase difference between the clock signal for generating first and second switching signal to have a waveform, respectively based on the summed signal summing may include a phase tracking for generating a frequency reference signal. ;