一种快速响应数字COT控制Buck变换器  

A Fast Response Digital COT Control Buck Converter

作　　者：胡怀志 甄少伟[1] 白正杨 王睿[1] 谢泽亚 张波[1] HU Huaizhi;ZHEN Shaowei;BAI Zhengyang;WANG Rui;XIE Zeya;ZHANG Bo(State Key Lab.of Elec.Thin Films and Integr.Dev.,Univ.of Elec.Sci.and Technol.of China,Chengdu 610054,P.R.China)

机构地区：[1]电子科技大学电子薄膜与集成器件国家重点实验室,成都610054

出　　处：《微电子学》2021年第5期690-695,共6页Microelectronics

基　　金：“十三五”装备预先研究项目(31513030209)。

摘　　要：提出了一种数字恒定导通时间(COT)控制的DC-DC Buck变换器。通过跨导放大器、流控振荡器(CCO)和数字滤波器对电感电流进行采样,形成电流内环。在基于ADC、PI补偿器的电压外环输出信号上叠加由误差电流、CCO产生的斜坡补偿信号,最终形成双环控制的Buck变换器电路。提出的数字谷值电流模COT控制方法采用数字电流内环和额外的斜坡补偿方式,加快了电路的瞬态响应,同时保持了数字电源高输出精度的特性。该Buck变换器在输入电压5V、输出电压3.3V、开关频率1MHz下进行了仿真验证。仿真结果表明,负载上阶跃和下阶跃响应时间分别为11μs和17μs。A DC-DC buck converter controlled by a digital Constant On Time(COT)was proposed.A current sampler composed of a transconductance amplifier,a Current Controlled Oscillator(CCO)and a digital filter was used to sample the inductor current to form a current inner loop.The slope compensation signal generated by the error current and CCO was superimposed on the voltage outer loop output signal based on the ADC and PI compensator,and finally a buck converter circuit controlled by the double loop was formed.The proposed digital valley current mode COT control method used a digital current inner loop and an additional slope compensation scheme to accelerate the transient response of the circuit while maintaining the high output accuracy of the digital power supply.The proposed buck converter had been simulated and verified under an input voltage of 5V,an output voltage of 3.3V,and a switching frequency of 1MHz.The simulation result showed that the up-step and down-step response of the load reached 11μs and 17μs,respectively.

关 键 词：数字COT控制 电流采样 斜坡补偿 BUCK变换器 

分 类 号：TN432[电子电信—微电子学与固体电子学]