锁相环中的充电泵电路的研究

Research on Circuitry of Charge Pump in Phase-Locked Loop

针对消除传统电荷泵电路存在的MOS开关的电荷注入效应,时钟馈通效应,电荷泄露和充放电电流失配等产生的锁相环的相位偏差问题,设计了两种新型的电荷泵电路.这两种电路的设计和仿真采用了0.6μm CMOS工艺,电源电压为5V,功耗分别为0.65 mW和0.7 mW.仿真结果表明,两种新型电荷泵电路的转换速度得到了提高,输出电压近似于电源电压到地的全摆幅并具有稳定的充放电步长,可用于高速锁相环电路.

Two novel structure of charge-pump circuitry for overcoming the traditional charge-pump＇s problems of phase-offset in PLL is designed. The circuits design and simulation are based on 0. 6μm CMOS technology, the power supply is 5 V and the power consumptions of two charge-pump are 0. 65 mW and 0. 7 mW. Simulation resuits show that the charge-pump switch speed is increased, the output voltage is close to rail to rail of power supply and charge and discharge step of output voltage is equal and： stable. The circuit has an excellent performance for high-frequency PLL application.