Operation and design of VHF self-oscillating DC-DC converter with integrated transformer

Abstract

The paper presents a self-oscillating DC-DC integrated converter which is operable in the frequency range of 200MHz-260MHz. The circuit includes a cascoded power stage, an integrated transformer, duty-cycle detector, and pulse shaper. The primary of the transformer provides the transmission of power to the converter load. The secondary, via detector and shaper, provides the feedback signal to the gates of cascoded transistors in the power stage. A detailed analysis of the converter operation is given. The conditions for a smooth start-up are indicated as well. The converter layout is provided. The circuit was designed and simulated in 45 nm CMOS technology, and the calculated operation parameters are compared with that of the extracted from layout converter.