用于锁相环的低失配CMOS电荷泵设计

Design of a Low Current Mismatch Charge Pump for Phase-locked Loops

设计了一种用于锁相环的低失配CMOS电荷泵电路,采用互补差分输入。互补差分管的使用有效地解决了电荷泵的时钟馈通和电荷注入等非理想现象。同时,利用自举的方法消除了电荷共享现象。在电路和版图的设计中,充分考虑了对称性对电流失配的影响。本电荷泵电路基于新加坡Chartered0.25μmN阱CMOS工艺实现,采用Candence中的Spectre仿真工具进行仿真,电源电压为3.3V。测试结果表明,在本芯片需要的各种电荷泵电流下其失配都低于0.65%。本电荷泵电路已应用于射频调谐器当中。

The design and measurement of an improved charge pump structure have been proposed in this paper and differential input was used in this cirrcuit. The usage of complementary and differential transistors has worked out the non-ideal effects of the charge pump such as the clock feed through, charge injection. Meanwhile, bootstrapping has been used for eliminating charge sharing. And, the symmetry has been carefully considered during the design of the circuit and layout. The result of the measurement has been given in this paper, it shows that the mismatch of all the charge pump current used in this chip is less than 0. 65 %. The charge pump has been designed using Chartered 0. 25 um N-Well CMOS process and simulated by the Spectre in Candence. The supply voltage is 3.3V. And this charge pump circuit has been applied in RF receiver.