CLASS-D AMPLIFIER HAVING MIXED SIGNAL FEEDBACK CONTROL

摘要

A Class-D amplifier includes an analog-to-digital converter (ADC), a digital filter, a digital pulse width modulation (PWM) unit, a pre-driver unit, and an output driver. The ADC is configured to receive an input signal and one or more feedback signals, and to generate a first digital signal. The digital filter, the digital PWM unit, and the pre-driver unit are configured to generate control signals based on the first digital signal. The output driver is configured to generate an output signal based on the control signals. A first feedback path is defined as from a first output node of the output driver to a first input node of the ADC; and a second feedback path is defined as from a second output node of the output driver to a second input node of the ADC. The first and second feedback paths are free from a low-pass filtering device.

主权项

1. A Class-D amplifier, comprising:
an analog-to-digital converter (ADC) having a first input node, the ADC being configured to:
receive a first analog input signal and a first feedback signal at the first input node of the ADC, andgenerate a first digital signal based on the first analog input signal and the first feedback signal; a digital filter configured to generate a second digital signal based on the first digital signal; a digital pulse width modulation (PWM) unit configured to generate a first PWM signal based on the second digital signal; a first pre-driver unit configured to generate a first set of control signals based on the first PWM signal; a first output driver having an output node, the first output driver being configured to generate a first output signal at the output node of the first output driver based on the first set of control signals; and a first feedback unit configured to generate the first feedback signal based on the first output signal, a first feedback path being defined as from the output node of the first output driver through the first feedback unit to the first input node of the ADC, and the first feedback path being free from a low-pass filtering device that has a cutoff frequency lower than a sampling frequency of the ADC.