An ultra-low distortion electronic amplifier wherein the global dominant pole is formed by the selection of circuit and component arrangement within the input stage, such that the global dominant pole, is of third order, at audio frequencies. This audio power amplifier implements a high order global dominant pole with the use of operational amplifiers, and this high order dominant pole is distributed across both the voltage amplification stage and input stage without adverse reduction in the slew rate. The amplifier has increased negative feedback at audio and ultrasonic frequencies, giving a reduction in distortion across the entire audio band and some of the lower ultrasonic band.
An audio amplification device includes an input for receiving an input audio signal and an output for delivering an output audio signal and an amplifier (OA1) comprising a differential pair of MOS transistors. The gate of the first transistor is coupled to the input of the device. The gate of the second MOS transistor receives a reference voltage which takes the form of a rising ramp when the power is turned on. The drain of one of the transistors is coupled to the output. The amplifier also includes a biasing circuitry for biasing the bulk of the transistors to a first voltage level approximately equal to a supply voltage at the beginning of the reference voltage ramp, and to a second voltage level (V.sub.BB) approximately equal to the voltage of their source at the end of the ramp. The generation of a pop is thus avoided when the power is turned on, while still benefiting from an optimum PSRR in the normal operation phase.
An amplifier circuit comprises a first capacitance having one end that communicates with an input of a first amplifier stage. An amplifier has a first gain, an input that communicates with an opposite end of the first capacitance, and an output. A second capacitance has a first end that communicates with the output of the amplifier and an opposite end that communicates with an input of a second amplifier stage. A broadband buffer has an input that communicates with the output of the amplifier and an output that communicates with the one end of the second capacitance.
