用于分数频率综合器的改进型电荷平均电荷泵

介绍了一种改进型的电荷平均电荷泵以及相应的电路实现.文章在对Yido Koo首先提出的电荷平均电荷泵结构分析的基础上提出了改进型的实现方式.相比于原结构,这种新型电路能够节省1/3的功耗并且消除了原先结构在实际实现中的一些问题.Spec-tre Verilog行为级仿真结果证明该结构能够有效降低杂散能量.本文同时设计了一个针对分数分频比为1/3的小数频率综合器的改进型电荷共享电荷泵,并通过多层次仿真的方式来验证其可行性.从仿真结果可以看出,这种新结构输出电压稳定,从而能够有效消除频率综合器中的分数杂散.

An Improved Charge-Averaging Charge Pump for a Fractional-N Frequency Synthesizer

An improved charge-averaging charge pump and the corresponding circuit implementation are presented. Thecharge-averaging charge pump proposed by Koo is analyzed and a new scheme is proposed. This new scheme decreasespower by 1/3 and eliminates the practical defects in the original. Spectre Verilog behavioral simulation results show thatthe proposed scheme can strongly reduce the energy of spurs. Circuit implementation of this new charge pump for a fre-quency synthesizer with a fractional division ratio of 1/3 is then presented and multi-level simulation is performed to vali-date its feasibility at the circuit level. The simulation results show this new scheme outputs a flat voltage curve in a lockedstate and can thus effectively suppress fraction spurs.