基于有源电容倍增器的新型电荷泵DC-DC变换器

电荷泵中浮置电容是影响输出特性的关键因素,针对大容量浮置电容难以集成的问题,提出利用电流传输器构成有源电容倍增器代替浮置电容的方法,可使等效的浮置电容容量提高1~3个数量级.利用PSPICE软件对反压及倍压电荷泵分别在采用有源电容倍增器和理想电容的情况下进行仿真,对比分析的结果说明采用有源电容倍增器的电荷泵电路仅需要很小的电容就能得到与外加大容量浮置电容电荷泵电路相同的输出特性(实例中100pF可等效50nF),从而基于有源电容倍增器的电荷泵将更易于全单片集成.

A New Charge Pump DC-DC Converter Based on Active Capacitance Multiplier

The floating capacitor is a key factor to determine the output characteristics of a charge pump.In order to overcome the difficulty in fabrication of the large capacitors in monolithic integrated circuits,a technique of replacing the floating capacitor by an active capacitance multiplier is proposed in this paper.Equivalent capacitance value of the active capacitance multiplier can be enlarged in 1~3 orders of magnitude.PSPICE simulations of the output characteristics were carried out for charge pump doublers and charge pump inverters for the different designs of adopting the capacitance multiplier and a normal capacitor,respectively.The simulation results show that the same output characteristics can be obtained from the new charge pump with a capacitor much smaller than that adopted in the normal charge pump products.For example,100 pF in the new is equivalent to 50nF normally in this work.Employing the active capacitance multiplier,therefore,the new charge pump is much easier to be fabricated in fully integrated realizations with on-chip capacitor.