用于相变存储器的超低输出纹波2X/1.5X电荷泵

本文针对相变存储器编程驱动电路,提出了一种超低输出电压纹波的开关电容型电荷泵。该电荷泵可根据输入电压的不同,自适应工作在2X/1.5X升压模式之间,以获得更高的电源转换效率。相比于传统开关电容型电荷泵,在充电阶段泵电容被充电至预先设定的电压值Vo-VDD(Vo为预期的输出电压)；放电阶段,泵电容串联在输入电压VDD与输出端,通过此方法将电荷泵输出端电压稳定在Vo,并有效的降低了由于电荷分享所造成的输出纹波。在中芯国际40nm标准CMOS工艺模型下,对电路进行了仿真验证,结果表明在输入电压为1.6-2.1V,输出2.5V电压,最大负载电流为10mA,输出电压纹波低于4mV,电源效率最高可达91%。

A novel low ripple charge pump with a 2X/1.5X booster for PCM

A low ripple switched capacitor charge pump applicable to phase change memory (PCM) is presented. For high power efficiency, the selected charge pump topology can automatically change the power conversion ratio between 2X/1.5X modes with the input voltage. For a low output ripple, a novel operation mode is used. Compared with the conventional switched capacitor charge pump, the flying capacitor of the proposed charge pump is charged to V_o-V_in during the charge phase (V_o is the prospective output voltage). In the discharge phase, the flying capacitor is placed in series with the V_in to transfer energy to the output, so the output voltage is regulated at V_o. A simulation was implemented for a DC input range of 1.6-2.1 V in on SMIC standard 40 nm CMOS process, the result shows that the new operation mode could regulate the output of about 2.5 V with a load condition from 0 to 10 mA, and the ripple voltage is lower than 4 mV. The maximum power efficiency reaches 91%.