Method of preventing abrupt voltage changes at the outputs of a pair of amplifiers and control circuit for a pair of amplifiers self-configuring in a bridge configuration

摘要

A method of preventing abrupt voltage changes at the outputs of a pair of amplifiers and a common mode control circuit of a pair of amplifiers that reduce EMI and increased distortions occur when the correlation between the signals that are fed to the four channels of the audio system diminishes has been found.;This result is attained by properly generating for each amplifier a reference potential as a saturated replica of the respective differential input signal of the amplifier that saturates when the amplifier switches to a bridge configuration.;This method is implemented in a common mode control circuit for a pair of amplifiers self-configuring in a bridge configuration for driving a first load and in a single-ended mode of operation of one of the amplifiers for driving the first load, in function of the level of a differential input signal, comprising for at least one of the pair of amplifiers a common mode feedback differential amplifier, a storage capacitor connected between any one of the two inputs of the feedback amplifier and a node at a reference potential, by providing the common mode control circuit of means for generating this reference potential.