A fully integrated 2 V input 2:1 switched capacitor converter using CMOS-type class-D oscillator-based driver achieving 61 mW driving loss at 480 MHz

Abstract In this paper, an ultra-high-speed, low-loss gate driver circuit using a CMOS-type class-D oscillator and a switched capacitor (SC) converter directly driven by it are proposed and demonstrated. Conventional buffer drivers suffer from large power losses, making it difficult to operate SC converters in the several hundreds of MHz range. The proposed driver circuit achieves low-loss operation in this frequency range by employing an inductor-based constant-current gate drive that self-oscillates utilizing CMOS-type class-D oscillator. This approach enables a significant reduction of the flying capacitor value in the SC converter. The proposed oscillator driver and SC converter are implemented using only 1.0 V transistors in a 65 nm CMOS process. The oscillator inductors and flying capacitors are all integrated on-chip. The measurement results show that the SC converter can be driven at 480 MHz with a driver power loss of 61 mW, achieving a maximum efficiency of 60.2% at an output current of 350 mA.