首页>
外国专利>
Fractional-N PLL Using Multiple Phase Comparison Frequencies to Improve Spurious Signal Performance
Fractional-N PLL Using Multiple Phase Comparison Frequencies to Improve Spurious Signal Performance
展开▼
机译:小数N分频PLL使用多个相位比较频率来改善杂散信号性能
展开▼
页面导航
摘要
著录项
相似文献
摘要
SEARCHES A fractional spur compensation technique is implemented in a fractional-N PLL using multiple phase comparison frequencies Fpd, one of which is selected for any channel frequency Fch in a target frequency band to obtain a selected offset frequency Fos between the channel frequency Fch and its primary fractional spur throughout the target frequency band. Other features of an exemplary implementation of the fractional spur compensation technique include (a) maintaining the phase comparison frequency at less than a predetermined maximum value, (b) using a programmable reference frequency multiplier with selectable multiplication factors and/or a programmable reference frequency divider with selectable divide ratios to generate multiple phase comparison frequencies derived from a predetermined reference frequency Fref, and (c) using a programmable charge pump to select different charge pump currents for respective phase comparison frequencies to reduce loop gain variation.
展开▼