基于SMIC 40nm CMOS工艺,提出了一种改进型电荷泵电路。在传统电荷泵锁相环中,电荷泵存在较大的电流失配,导致锁相环产生参考杂散,使锁相环输出噪声性能恶化。设计的电荷泵电路在电流源处引入反馈,降低了电流失配。仿真结果表明,在供电电压为1.1V,电荷泵充放电电流为0.1mA,输出电压在0.3~0.7V范围变化时,电荷泵的电流失配率小于0.83%,锁相环的输出参考杂散为-65.5dBc。 Based on the SMIC 40nm CMOS process, an improved charge pump circuit is proposed. In the traditional charge pump phase-locked loop, the charge pump has a large current mismatch, resulting in a reference spur-phase lock loop, so that the phase-locked loop output noise performance degradation. The designed charge pump circuit introduces feedback at the current source, reducing the current mismatch. Simulation results show that the current mismatch rate of the charge pump is less than 0.83% when the supply voltage is 1.1V, the charge-pump charge-discharge current is 0.1mA, and the output voltage is in the range of 0.3 ~ 0.7V. The output reference of the PLL Is -65.5dBc.