采用有限状态机控制的升降压双通路高效率电荷泵

针对诸如系统芯片中模拟和数字模块需工作在不同电源电压下的要求,提出一种可同时提供双路输出且具有多种增益模式的电荷泵,它仅利用一组开关电容阵列,根据输入电压与负载电流的变化自动为双通路选择合适的增益对,从而在提供稳定的输出电压同时使电荷泵具有较高的转换效率。专门引入增益跳变技术,改善了增益过渡的平滑性,进一步提高了转换效率。整个调制过程采用数字状态机控制,电路结构简单,响应速度快。芯片采用TSMC 0.35μm混合信号CMOS工艺设计并制造,仿真与测试结果显示设计目标均已实现,能够同时提供稳定的1.8 V和5.0 V的双路输出,动态响应迅速,转换效率比传统多增益模式电荷泵提高了10%以上。

An Efficient Step-up and Step-down Dual-output Charge Pump Controlled by Finite State Machine

To provide different supply voltages requested by analog and digital modules on system on a chip(SOC) respectively,a synchronous dual-output charge pump with multiple gain modes was proposed.By using one set of switch-capacitor array alone,it can automatically choose the proper gain pairs according to the input voltage and the load current so that the stable dual outputs with high efficiency are provided.A novel gain-hopping technique was proposed to increase efficiency further by smoothing the transition at gain-switching.A digital state machine controller was designed to realize the modulation strategy with fast transient response and simple circuit structure.The charge pump was designed and fabricated in a TSMC 0.35 μm mixed-signal CMOS process.Both the simulation and tested results show that the proposed charge pump is able to generate stable output voltages of 1.8 V and 5.0 V synchronously with fast dynamic response.And its efficiency is about 10% higher than the conventional multi-gain mode charge pumps.