Triple buck converter – an efficient low-distortion switch-mode power amplifier topology

Abstract

A switch-mode power amplifier topology that can achieve both a high conversion efficiency and low-output signal distortion is introduced. Such systems are desirable for ultra-high precision amplifiers that, for example, drive actuators in nanometre-accuracy mechatronic positioning applications in integrated semiconductor manufacturing. An efficient Class-D power stage, which is limited in output signal quality due to its inherent half-bridge interlock time, is combined through a magnetically coupled inductor with a dual buck conversion stage that does not require interlock time and, due to its circulating bias current that defines the half-bridge switching waveforms, achieves very low-harmonic output signal distortion. The control system can seamlessly adjust the current sharing of the two converter stages such that overall conversion efficiencies over 95% and output total harmonic distortion values below −100 dB are achievable at power levels up to several kilowatts. Detailed computer simulations demonstrate the feasibility of the concept.

Keywords

• bridge circuits
• inductors
• harmonic distortion
• dc-dc power convertors
• mechatronics
• amplifiers
• power convertors
• switched mode power supplies
• switching convertors
• power amplifiers
• power levels
• triple buck converter
• low-distortion switch-mode power amplifier topology
• high conversion efficiency
• low-output signal distortion
• ultra-high precision amplifiers
• nanometre-accuracy mechatronic positioning applications
• integrated semiconductor manufacturing
• efficient class-d power stage
• inherent half-bridge interlock time
• dual buck conversion stage
• half-bridge switching waveforms
• low-harmonic output signal distortion
• converter stages
• conversion efficiencies
• output total harmonic distortion values
• noise figure -100.0 db