Patent ID: 7113032

Claim:
A multi-channel power amplifier for driving a plurality of loads, each load associated with a respective channel of a power stage of the power amplifier, each channel of the power stage comprising a pair of operational amplifiers, first and second, one operational amplifier of each channel being connectable through switches either in a bridge configuration with the other operational amplifier or in single-ended configuration to a constant reference voltage for driving the load of the respective channel, the power amplifier further comprising circuit means for comparing the signal levels of said channels with at least a threshold and outputting a logic control signal for said switches, wherein said circuit means comprise: at least a window comparator of said signal level generating a comparison logic signal; a zero-cross detector of said signal level generating a zero-cross logic signal; a logic circuitry input with said zero-cross logic signal and said comparison logic signal and generating said logic control signal for configuring said first operational amplifier in an output bridge configuration when the signal level remains outside the window of said comparator and for configuring said first operational amplifier in single-ended output configuration when the signal level remains within the window of said comparator for at least a pre-established time interval following a zero-cross event.