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A Wide-Bandwidth 2.4 GHz ISM Band Fractional-/78 PLL With Adaptive Phase
提出一种快速自适应的相位噪声消除技术,应用于2.4 GHz ISM频段的CMOS PLL IC。
730 kHz带宽, 12 MHz参考频率, 101 dBc/Hz@100 kHz, 124 dBc/Hz@3 MHz, 35 μs最差稳定时间
自适应校准相位噪声消除CMOS PLLISM频段动态电荷泵
▸创新点1:自适应相位噪声消除技术(方法创新)。该技术通过快速自适应校准,显著降低了相位噪声,使1/6分数PLL在低参考频率下实用化,最差情况下100 kHz和3 MHz偏移处的相位噪声分别为-101 dBc/Hz和-124 dBc/Hz,且自适应校准的最差建立时间仅为35 μs。
▸创新点2:动态电荷泵偏置技术(电路创新)。该技术通过动态调整电荷泵的偏置电流,有效降低了功耗,同时保持了PLL的性能稳定性,提高了系统的能效比。
▸创新点3:片上环路滤波器(系统创新)。该滤波器集成在芯片内部,减少了外部元件的需求,简化了系统设计,同时优化了PLL的带宽和相位噪声性能,实现了730 kHz的带宽。
▸创新点4:快速自适应校准技术(方法创新)。该技术显著缩短了PLL的建立时间,提高了系统的响应速度,适用于需要快速频率切换的无线通信系统。
Abstract
A fast-settling adaptive calibration technique is pre- sented that makes phase noise cancelling /1/6 fractional- PLLs practical for the low reference frequencies commonly used in wire- less communication systems. The technique is demonstrated as an enabling component of a 2.4 GHz ISM band CMOS PLL IC with a 730 kHz bandwidth, a 12 MHz reference, and an on-chip loop filter. In addition to the adaptive calibration technique, the IC incorpo- rates a dynamic charge pump biasing technique to reduce power dissipation. The worst-case phase noise of the IC is 101 dBc/Hz and 124 dBc/Hz at 100 kHz and 3 MHz offsets, respectively, and the adaptive phase noise cancellation technique has a worst-case settling time of 35 s. The IC is implemented in 0.18 m CMOS technology. It measures 2.2 2.2 mm/50, and its core circuitry con- sumes 20.9 mA from a 1.8 V supply.