Push-pull switching power amplifier with sliding-mode control

Abstract

In this paper, a sliding-mode control technique is used to implement the control loop in a switching amplifier stage based on two step-down buck power converters operating in push-pull mode. By means of a discontinuity surface that uses the four state variables of the power converter, the authors obtain a large bandwidth suitable for audio applications. The presence of a first order compensating network assures a perfect tracking of the input signal.