Design Of Digital SIDO Switching Converter Based On Charge Conservation And Frequency Conversion Control

With the rapid development of 5G communication and mobile Internet information technology,many mobile intelligent terminals expect to improve their performance while devices tend to be light and portable.In order to meet the requirements of high performance,high integration and low power consumption of mobile terminal equipment,single-inductor multiple-output(SIMO)DC-DC converter is widely concerned.The analogue control scheme is a traditional implementation scheme of the switching power supply.However,the existence of the control circuit is prone to aging,temperature and noise interference,which limits the further improvement of the converter performance.The digital control circuit has the characteristics of flexibility and online adjustment and is becoming a research hotspot in the field of switching power supply design.SIMO DC-DC converter realizes multiple-channel dc outputs by reusing a single inductor,which greatly reduces the area of the chip.However,there are still some common problems in the study,such as large output ripple and cross-regulation,slow output voltage dynamic regulation rate and low conversion efficiency.In this paper,a new SIDO digital switching converter is proposed by studying the characteristics of single-inductor dual-output(SIDO)switching converter.The SIDO buck switching converter in continuous conduction mode(CCM)is taken as the research object to analyze the voltage-mode switch converter working condition.A method based on charge-balance and variable-frequency control is proposed to reduce the cross-regulation and improve the dynamic response of the converter when the load changes suddenly.The SIDO DC-DC converter has good stability and dynamic response in the field measurement environment and taking Xilinx Spartan6 FPGA as the feedback algorithm platform.The results show that the converter has low cross-regulation,fast dynamic response and low ripple.When the load current changes from 180 m A to 360 m A,the cross-regulation of the unchanged branch was only 0.055 mv /m A with a dynamic response time of 10 μs,while the self-regulation of the changed branch was 0.55 mv /m A with a dynamic response time of 180 μs.The output voltage ripple in the dynamic range of 2 V-6 V input voltage was about 3 % of the output voltage.