| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a digital power amplifier the size of which can be reduced without degrading performance. Ž<P>SOLUTION: The digital power amplifier has: an output part 30 which includes a pair of switching elements connected between high and low power voltages and has two output terminals connected to two input terminals of load; a current control oscillation part 13 which outputs a positive phase and negative pulse signals for driving the switching elements, oscillates the positive and negative pulse signals of prescribed frequency higher than a signal band having a prescribed Duty factor, and changes the Duty factor or oscillation frequency in accordance with an external control signal; a feedback loop 50 which performs phase operation so that the signal band does not oscillate but an oscillation frequency component performs self-oscillation, adjusts gain, and returns it to an input step; and at an input step, a comparator 11 which generates the external control signal for controlling an oscillation signal on the basis of an input signal and a feedback signal. Ž<P>COPYRIGHT: (C)2010,JPO&INPIT Ž
|
