一种带补偿调节机制的低失配电荷泵

A Low Mismatch Charge Pump with Offsetting Adjustment Mechanism

传统运放型电荷泵的电流失配比易受工艺参数、环境温度等因素影响,从而产生较大的输出纹波电压,恶化锁相环的噪声性能。针对这种情况,基于55 nm CMOS工艺,提出一种应用于射频锁相环系统的新型电荷泵。该电荷泵在电流源之间引入反馈,在降低电流失配的同时加入了补偿调节电路,降低了因工艺参数、环境温度等因素变化而导致电流失配比恶化的程度。电荷泵的版图面积为0.017 mm^2。后仿真结果表明,在电源电压为1.3 V的条件下,输出电流为120μA,输出电压在0.25~1 V范围内变化时,TT工艺角下电流失配比仅约为0.1%,而同一电荷泵在不增加补偿调节模块下的失配比为1.5%。

In view of the facts that the current mismatch ratio of traditional op-amp charge pump structure was easily affected by process parameters and ambient temperature,which resulted in a large output ripple voltage and deteriorated the noise performance of PLL,a novel charge pump circuit for RF PLL system was designed in a 55 nm CMOS technology.The proposed charge pump introduced feedback between current sources to reduce the current mismatch.It also added compensation regulation circuit to reduce the deterioration of current mismatch ratio caused by the variation of process parameters and ambient temperature.The layout area of the charge pump was 0.017 mm^2.Post-simulation results showed that the current mismatch ratio was only about 0.1%when the output voltage varied from 0.25 V to 1 V with the output current of 120μA at 1.3 V supply voltage and TT corner,while the current mismatch ratio of the same charge pump without compensation and regulation module was 1.5%.