应用于Buck转换器的固定斜率片上软启动方法  

The fixed-slope on-chip soft start method applied to Buck converter

作　　者：郭仲杰 邱子忆 杨媛[1] 余宁梅[1] GUO Zhongjie;QIU Ziyi;YANG Yuan;YU Ningmei(School of Automation and Information Engineering,Xi’an University of Technology,Xi’an 710048,China)

机构地区：[1]西安理工大学自动化与信息工程学院,陕西西安710048

出　　处：《华中科技大学学报(自然科学版)》2025年第3期159-166,共8页Journal of Huazhong University of Science and Technology(Natural Science Edition)

基　　金：国家自然科学基金资助项目(62171367);陕西省重点研发计划资助项目(2021GY-060);西安理工大学校企协同基金资助项目(252062213)。

摘　　要：针对传统固定时间软启动面对不同输出电压启动时电源电压电流变化较大的问题,提出了一种应用于Buck型转换器可片内集成的固定斜率软启动方法,主要机理是通过反馈系数采样与固定斜率基准电压有机结合,通过将软启动充电电流等效为脉冲电流,以片内集成的小电容实现了缓慢上升的基准电压,对于设定的不同输出电压都能够按照固定的斜率启动;通过毛刺消除技术解决了脉冲周期引起的充电电流尖峰,提升了软启动时间的精确控制;软启动方法通过将电容分压网络代替传统电阻分压网络消除了产生的直流功耗,软启动完成时平滑地过渡到稳态工作阶段,软启动模块自动关闭,降低了系统静态功耗.基于0.18μm高压BCD工艺对提出的方法进行了具体电路设计与后仿真验证,结果表明:在芯片输出范围0.9~4 V内输出电压都基本保持5 V/ms的固定斜率启动,斜率控制精度可达98%.软启动电路有效地消除了满载3 A与空载0 A的状态下启动时产生的浪涌电流,整体浪涌电流减小了44%,输出电压能平稳上升并平滑过度到稳态工作阶段.Aiming at the traditional fixed-time soft-start facing the problem of different power supply stresses(device voltage and current stresses)when starting with different output voltages,a fixed-slope soft-start method that can be integrated on-chip for Bucktype converters was proposed.The main mechanism is through the feedback coefficient sampling and fixed-slope reference voltage organic combination,through the soft-start charging current is equivalent to the pulse current,with the on-chip integration of small capacitors to achieve a slow rise in the reference voltage,for the setting of the different output voltages are able to start in accordance with a fixed slope.The charging current spike caused by the pulse cycle is solved by the burr elimination technique,which improves the precise control of the soft-start time.The soft-start method eliminates the direct current(DC)power consumption generated by substituting the capacitor voltage divider network for the traditional resistor voltage divider network,and the soft-start completes the soft-start by smoothly overpassing to the steady state operation stage,and the soft-start module automatically shuts down,which reduces the static power consumption of the system.Based on the 0.18μm high-voltage BCD process,specific circuit design and post-simulation verification were conducted for the proposed method.The results show that the output voltage basically maintains a fixed slope of 5 V/ms for startup within the chip output range of 0.9~4 V,and the slope control accuracy is up to 98%.The soft-start circuit effectively eliminates the inrush current generated during the startup of full load 3 A and no load 0 A,the overall inrush current is reduced by 44%,and the output voltage can rise smoothly to the steady state operation stage.

关 键 词：直流转直流(DC-DC) 固定斜率 软启动 片内集成 低功耗 

分 类 号：TN86[电子电信—信息与通信工程]