Patent ID: 8488812

Claim:
A biasing circuit, comprising: an output terminal configured to be coupled to an acoustic transducer; a biasing terminal configured to receive from a voltage-booster stage a boosted voltage for biasing the output terminal; a filter coupled between the biasing terminal and said output terminal, and configured to implement filtering of disturbances on said boosted voltage; a first switch configured to provide a current path between said biasing terminal and said output terminal during a start-up step of said biasing circuit, and configured to allow the filter to filter the disturbances once said start-up step has terminated, the first switch having a control terminal; and a control stage having a first output terminal electrically coupled to the control terminal of the first switch, the control stage being configured to provide a first control signal at the first output terminal of the control stage and control the first switch with the first control signal; a high-impedance resistor element; an amplifier having an input and configured to process an electrical output quantity of said acoustic transducer; and a second switch connected in parallel to said high-impedance resistor element, the second switch having a control terminal electrically coupled to a second output terminal of the control stage and being configured to short-circuit said high-impedance resistor element during said start-up step and couple said input of the amplifier to a reference-voltage line.