A Peak Current Mode Buck DC-DC Converter with Programmable Phase Shifting for Parallel Applications

In order to solve the problem of limited power capacity and switch stress in a single power supply, this paper designs a multi-phase interleaved parallel high-current Buck DCDC converter. The converter is based on peak current mode (PCM) to meet the power supply requirements of the equipment and reduce output voltage and current ripple. This paper proposes a programmable phase shift circuit. By setting the phase shift of the switching clock of the parallel branch converter, the power output of the converter can be easily expanded to a parallel structure of 2 to 12 phases. The circuit proposed in this paper is designed based in the SMIC $0.18 \upmu\mathrm{m}$ 5V CMOS process for circuit and layout design. The simulation results show that when the input voltage is 5V, the output voltage is 1.5V, the switching frequency is 1 MHz, the single-phase output is 5A, and the four-phase parallel output is 20A, the output voltage ripple is 3.56 mV and 0.61 mV respectively, and the output current ripple is 11.87 mA and 8.11 mA respectively, achieving the performance of high current and low ripple output.