摘要
传统电荷泵因电流失配引起输出电压的纹波,影响锁相环的噪声并恶化杂散性能。基于输出阻抗增强技术实现了宽动态范围下维持较高的静态电流匹配度,采用数字校准技术实现了充放电电流的动态失配校准。基于源极开关结构克服时钟馈通和电荷共享非理想效应,采用运放钳位电压消除输出电压通过沟道长度调制效应造成的失配。通过比较器检测输出电压的变化来推断充电电流和放电电流的失配关系,设计数字校准逻辑电路和校准补偿电流电路对判定失配电流反向进行补偿实现校准。基于CMOS 55 nm工艺对该电路进行了设计,后仿真结果显示,在1.2 V电源电压下,100μA电流电荷泵输出动态范围为0.22~1.06 V,静态电流失配小于0.12%,校准功能将动态失配从2.4μA降低至0.27μA,芯片面积为0.039 mm^(2)。
Conventional charge pumps cause ripple in the output voltage due to current mismatch,which negatively impacts the noise and spurious performance of the PLL.A digital calibration technology and output impedance enhancement structure with high static current match was designed to achieve dynamaic mismatch calibration.Based on the source switch structure,the design overcomes the non-ideal effects of clock feedthrough and charge sharing,and utilizes an operational amplifier to clamp the voltage and eliminate the mismatch caused by channel length modulation effects in the output voltage.The mismatch relationship between the charging and discharging currents is inferred by detecting variations in the output voltage through a comparator.A digital calibration logic circuit and a compensation current circuit are designed to correct the determined mismatch current in the reverse direction,achieving calibration.The circuit is designed using a CMOS 55 nm process.Post-simulation results show that with a 1.2 V power supply,the output dynamic range of the 100μA current charge pump is 0.22–1.06 V,with a static current mismatch of less than 0.12%.The calibration function reduces the dynamic mismatch from 2.4μA to 0.27μA,and the chip area is 0.039 mm^(2).
作者
陶磊
李婷
马梓铭
TAO Lei;LI Ting;MA Ziming(CETC Academy of Chips Technology,Chongqing 401332,P.R.China)
出处
《微电子学》
北大核心
2025年第1期120-126,共7页
Microelectronics
关键词
电荷泵
低电流失配
自动校准
Charge pump
Low current mismatch
Automatic frequency calibration
