A low-power high-SFDR CMOS direct digital frequency synthesizer

A low-power high-SFDR CMOS direct digital frequency synthesizer (DDFS) is presented. Several design techniques, including a cell-based lookup table, a power aware parameters selection method, a reduced multiplier, a speeded-up adder/subtracter, an extra pipeline stage, and supply voltage scaling, are used to make the design more easily synthesizable and much more power efficient. A synthesized 0.35-μm DDFS, with an SFDR of -100 dBc, runs up to 100-MHz and consumes only 26.2-mW with a supply voltage of 1.7-V. The power efficiency is 0.26-mW/MHz, which represents an enhancement of more than 90% compared to the conventional DDFSs.