一种高性能低功耗直接数字频率合成器的设计

文章基于分段线性近似算法提出分段泰勒二阶近似算法，从频谱纯度分析了该算法的优越性，讨论了系数位数和分段数的选取，最后结合硬件优化的系统结构，设计实现了SFDR达102．3dB的数字频率合成器。综合结果表明，该算法实现的系统面积上要比分段线性近似算法的系统小20％，功耗上也小39．5％。与现有的其他数字频率合成器比较表明，在设计高频谱性能DDFS方面，其在功耗和面积上都具有较大优势。

A Design of High-Performance Low-Power Direct Digital Frequency Synthesizers

This paper presents new techniques to implement direct digital frequency synthesizers(DDFS)with piecewise 2nd-order-Taylor-series approximation based on piecewise-linear approximation. The algorithm's performance is analyzed in spectral purity. Selections of finite length coefficients and number of segments are discussed. Finally, a 102.3dB-SFDR direct digital frequency synthesizer is implemented with optimized circuit architecture. Synthesis results show that, the proposed DDFS circuits is 20% less than piecewise-linear approximation in area, and 39.5% lower in power. In high spectral performance design, the method proposed in this paper is superior in area and power compared with previously proposed approach.