High-performance audio amplifier

A high-power audio amplifier intended to control at least one loudspeaker, said amplifier comprising:

• a pre-amplification stage that receives an input signal;
• a power amplification stage, which is connected to the pre-amplification stage and supplies an output signal intended to power said at least one loudspeaker;
• the pre-amplification and power amplification stages comprising an upper part and a lower part mounted mirroring each other;
• a feedback supplying the pre-amplification stage with an image of the output signal,
• an upper power supply circuit, which is connected to the upper part of the power amplification stage, and enabling it to be powered by a first or a second power bus;
• a lower power supply circuit, which is connected to the lower part of the power amplification stage, and enabling it to be powered by a first or a second power bus;
• each power supply circuit comprising a MOSFET transistor and monitoring means, the MOSFET transistor being controlled by a supervision means so as to carry out switching between one or the other of the two power buses, the MOSFET transistor being connected to the second power bus via a fourth diode of which a first terminal is connected to the source of the MOSFET transistor, and a drain of the MOSFET transistor being connected to the first power bus, characterized in that each power supply circuit further comprises:
• a sub-circuit for assisting with charging said MOSFET transistor, comprising at least a first resistor, a first terminal of the first resistor being connected to a gate of the MOSFET transistor and a second terminal of the first resistor connected being to an interconnection point;
• a sub-circuit for assisting with discharging said MOSFET transistor comprising at least a second and a third resistor and a bipolar transistor;
• a base of the bipolar transistor being connected to a first terminal of the third resistor, its emitter being connected to the gate of the MOSFET transistor and its collector being connected to the source of the MOSFET transistor via the second resistor, a second terminal of the third resistor being connected to the interconnection point;
• and
• a voltage-shifting sub-circuit comprising a first diode mounted in parallel with a first capacitor;
• a first terminal of the first diode and a first terminal of the first capacitor being connected to a first interconnection node, which is itself connected to said interconnection point of said sub-circuit for assisting with discharging;
• a second terminal of the first diode and a second terminal of the first capacitor being connected to a second interconnection node, which is itself connected to said output signal.