A grounded-output 5-switch bipolar buck-boost converter topology for switching power amplifiers

Abstract

This work presents a switching converter topology which can boost and step down the supply voltage and can deliver both positive and negative voltages to a grounded load (bipolar converter topology with non-floating output). This topology, which uses five switches to perform the power conversion, is mostly intended for switching amplifiers, especially for applications which require both boosting and inverting the supply voltage (to supply bipolar voltage signals), and/or EMI-sensitive applications. Using a single-stage switching amplifier based on this 5-switch topology, it is feasible to supply a grounded load with a symmetrical bipolar voltage signal whose magnitude extends up to several times the magnitude of the supply voltage.