DIGITAL INPUT CLASS-D AMPLIFIER HAVING NEW STRUCTURE OF SWITCHED CAPACITOR FEEDBACK

摘要

PURPOSE: A digital input class-D amplifier having a new switched capacitor feedback structure is provided to improve PSRR(Power Supply Rejection Ratio) performance by correcting noise or an analog voltage value of VDD/VSS through feedback. CONSTITUTION: A DA(Digital-Analog) converter(510) converts an input signal in a digital signal form into an analog signal. A modulator(520) outputs an analog signal into a digital signal with a specific level. An output buffer amplifier(530) amplifies a digital signal. A switched capacitor(511) connects one end to an output end of the DA converter and connects the other end of an input end of the modulator. A voltage scaling unit(550) connects one end to the output end of the output buffer amplifier. A switching device(512) connects one end to the other end of the voltage scaling unit and connects the other end in between the output end of the DA converter and switches capacitor.