CLASS-D AUDIO AMPLIFIER COMPRISING A CIRCUIT FOR READING A CURRENT SUPPLIED BY THE AMPLIFIER TO THE LOAD, AND CORRESPONDING READING METHOD

摘要

A class-D audio-amplifier apparatus including a circuit (50) for reading a load current supplied by said amplifier to a load, said amplifier comprising a final stage, which includes a full-H bridge comprising a first half-bridge and a second half-bridge; said circuit (50) being configured for estimating said load current through reading of a current (I OUTP , I OUTM ) supplied by at least one power transistor (13b, 23b), by measuring a drain-to-source voltage (V DSLP ) thereof during an ON period. According to the invention, said apparatus comprises a sensing circuit (50) connected for detecting a first drain-to-source voltage (V SP ) from a transistor (13b) of the first half-bridge (12) and a second drain-to-source voltage (V SM ) from a corresponding transistor (23b) of the second half-bridge (22), said sensing circuit (50) comprising: a module (51) for computing a difference between said first detected drain-to-source voltage (V SP ) and said second detected drain-to-source voltage (V SM ); and a module (53) for performing an averaging operation on said difference to obtain a sense voltage value (V SENSE ) to be supplied to an analog-to-digital converter (54).