适合集成开关电容DC-DC变换器的浮地电容倍增器

Floating Capacitance Multiplier for Switched Capacitor DC-DC Converter IC's

针对在集成电路中制作大容量电容器的困难,提出了一种利用电流传输器提高集成电容器容量的方法,称之为连续可变浮地电容倍增器。分析了电容倍增的机理,建立了相应的关系式,在此基础上对用此浮地电容构成的一阶滤波器和开关电容DC-DC变换器进行了理论分析和PSPICE仿真。结果表明,利用电流传输器的阻抗变换作用,可使小容量的电容等效变换为较大容量的浮地电容,从而便于开关电容DC-DC变换器实现全单片集成。

A method to multiply the capacitance of an integrated capacitor using a current conveyor is proposed to overcome the difficulty in fabricating large capacitors in monolithic IC's. The theory of the capacitance multiplication is analyzed,and relevant formulas are established. A simulation is made on a first-order filter based on the continuously variable floating capacitance multiplier. Results show that small capacitance of an integrated capacitor can be transformed into a larger value of an equivalent floating capacitor,which facilitates the integration of a switched capacitor DC-DC converter into a smaller chip.