Patent ID: 7173483
Filing Date: 2007-02-06
Classification: H03F,H03K

Abstract:
1. A switching amplifier comprising: an oscillating circuit for generating an oscillating signal having a valley, a mean level, and a peak; a level shifting circuit for adjusting a voltage level of an original input signal to generate a first input signal and a second input signal such that the first input signal is identical to the original input signal except for referring to a first reference level, and the second input signal is identical to the original input signal except for referring to a second reference level, wherein the first reference level is between the mean level and the valley of the oscillating signal and the second reference level is between the peak and the mean level of the oscillating signal; a first control circuit for generating a first width-limited pulse-width-modulation (PWM) signal in response to the first input signal and the oscillating signal, the first width-limited PWM signal having a pulse each cycle with a width larger than or equal to a predetermined first width; a second control circuit for generating a second width-limited PWM signal in response to the second input signal and the oscillating signal, the second width-limited PWM signal having a pulse each cycle with a width larger than or equal to a predetermined second width; a first half-bridge switching circuit controlled by the first width-limited PWM signal for determining a potential at a first output terminal; and a second half-bridge switching circuit controlled by the second width-limited PWM signal for determining a potential at a second output terminal.