Integrated DC-DC converter design for improved WCDMA power amplifier efficiency in SiGe BiCMOS technology

Abstract

We present a DC-DC converter design for on-chip integration with a WCDMA power amplifier to provide supply voltage modulation and efficiency enhancement. It operates from a 3.3V supply using 0.35µm 'high-breakdown' CMOS transistors available in IBM's SiGe BiCMOS 6HP process. Five selectable output voltage levels are available ranging from 1.3V to 3.3V. The converter is optimized for operation at 88.7MHz. Simulation results show an average efficiency of 78.8% over power amplifier operating conditions and a peak enabled efficiency of 86%. CCM-DCM mode switching and transistor width switching are used to minimize losses at the different output voltage and current load levels.