锁相环中基于电流控制技术的电荷泵的设计

Design of Charge Pump based on Current Control Technology in PLL

锁相环能够跟踪输入信号的相位和频率,并输出相位锁定、低抖动的其他频率信号,广泛应用于通信系统中。高性能的锁相环芯片的设计,是当今通信领域研究的一个重点。文中对锁相环电路中的电荷泵电路模块进行改进,设计出一种带有电流控制技术的差分型电荷泵,实现了低功耗、高充放电速度的目的,并很好抑制电荷共享效应。同时通过电流模滤波器电路的设计,减小了整体电路的噪声,降低了功耗。

PLL could track the input signal phase and frequency, and output other phase-locked and low-jitter frequency signal. So it widely used in communication systems. Based on the modification of charge pump module in PLL circuit, the differential charge pump with current control technology is designed, thus achieving the purpose of low power consumption and high speed charging and discharging, including good inhibitory effect of charge sharing. Through the design of current-mode filter circuit, the noise of the overall circuit and the power consumption are effectively reduced.