一种应用于频率综合器的高性能全差分电荷泵电路  

A High-Performance Fully Differential Charge Pump for Frequency Synthesizer Applications

作　　者：杨振宇[1] 唐长文[1] 闵昊[1] 

机构地区：[1]复旦大学专用集成电路与系统国家重点实验室,上海201203

出　　处：《Journal of Semiconductors》2007年第12期1993-1998,共6页半导体学报（英文版）

摘　　要：提出了一种应用于频率综合器的全差分电荷泵电路.该电荷泵结构可以很好地克服沟道长度调制效应的影响,使充放电电流在宽输出电压范围内实现精确匹配,从而使频率综合器的压控电压纹波(ripple)很小.为了保证电荷泵的宽输出摆幅不受限制,还设计了一种输入范围接近轨到轨的共模负反馈电路.整个电路在1.8V SMIC0.18μm CMOS混合信号工艺下设计实现,芯片面积约为450μm×280μm,直流功耗约为1mW,测试得到的参考杂散的最差值为-73dBc,满足频率综合器的低杂散要求.A fully differential charge pump for a frequency synthesizer is proposed, The pump eliminates the effect of chan- nel-length modulation and makes the charging and discharging currents match perfectly in a wide output range to minimize the ripple of the control voltage, A common-mode feedback circuit with rail-to-rail input range is employed to ensure a large unrestricted swing of the charge pump. The proposed fully differential charge pump is designed and fabricated in a 1.8V SMIC 0.18μm CMOS mixed-signal process ; the chip area is about 450μm × 280μm;and the power dissipation is lmW. A refer-ence spur level of -73dBc is achieved in the worst case,satisfying the performance of the frequency synthesizer.

关 键 词：频率综合器 全差分电荷泵 电流匹配 电流复制 电压纹波 杂散 

分 类 号：TN73[电子电信—电路与系统]