| 摘要 |
PURPOSE:To provide the switching amplifier for speaker driving which can take out a large power without reducing the impedance of a speaker or using DC-DC converter to raise the supply voltage. CONSTITUTION:A PWM conversion circuit 20 which generates a PWM1 signal from an in-phase signal and a saw tooth wave and generates a PWM2 signal from an anti-phase signal and the saw tooth wave connects the PWM1 signal to a first push-pull circuit 31 and connects the PWM2 signal to a second push- pull circuit 32. The first push-pull circuit 31 is connected to a first smoothing circuit 71 through a first switching circuit 41, a first pulse transformer 51, and a first rectifying circuit 61, and the second push-pull circuit 32 is connected to a second smoothing circuit 72 through a second switching circuit 42, a second pulse transformer 52, and a second rectifying circuit 62, and first and second smoothing circuits 71 and 72 are connected to a speaker 80. |
