A 20 MHz 200-500 mA Monolithic Buck Converter for RF Applications

In an RF system power amplifiers (PAs) typically consume the most power. This paper presents a buck converter design optimised for a wideband code division multiple access (WCDMA) PA. The design approach taken focuses on the optimization of switch sizing based on the overall power losses of the system including the output inductor losses. The converter is optimised for 20 MHz switching and output currents in the range of 200-500 mA. Experimented results are presented on the fabricated converter, with a maximum measured efficiency of 82%.