| 摘要 |
PROBLEM TO BE SOLVED: To provide a switching amplifier circuit based on the PWM modulation system for realizing reduction in noise production and in the power consumption at input of a small level signal. SOLUTION: The switching amplifier circuit includes circuits 610, 611 that compare the phase of a reference phase signal 121 with the phase of switching PWM signals 132, 133 shaped by comparing an input signal 101 with a ramp waveform 123 and generate pulse signals 612a, 612b, 613a, 613b in response to a phase difference corresponding to the amplitude of the input signal. The pulse signals in response to the phase difference are supplied to bridge circuits 140, 141 for driving a load such as a speaker in place of an ordinary switching PWM signal. COPYRIGHT: (C)2005,JPO&NCIPI
|
