AMPLIFIER WITH ADJUSTABLE RAMP UP/DOWN GAIN FOR MINIMIZING OR ELIMINATING POP NOISE

摘要

A variable ramp up/down gain in a pre-power stage block of an audio amplifier may be used to reduce audible pops and clicks output by the audio amplifier. A controller may adjust the variable ramp up/down gain during operation of the audio amplifier. The variable ramp up/down gain may be implemented as a pulse width modulation (PWM) modulator/generator with a ramp-up and ramp-down gain under control of the controller. The variable ramp up/down gain smooths transitions of the offset between a pre-power stage block and a feedback loop and thus can reduce audible pops and clicks by reducing the offset that is amplified in the power stage block of the audio amplifier.

主权项

1. An apparatus, comprising:
an input node configured to receive an input analog signal for reproduction by a transducer; a pre-power stage block coupled to the input node and configured to process the input analog signal, wherein the pre-power stage block comprises a component with a configurable ramp up/down gain; a power stage block coupled to the pre-power stage block and configured to amplify the processing input analog signal; a feedback loop coupled between an output of the power stage and an input of the pre-power stage block; and a controller coupled to the pre-power stage block and configured to vary the configurable gain of the pre-power stage block during a transition of the feedback loop.