This paper presents a new way to design DDFSs by using+/-controlled D/ A converters, which perform not only the function of a D/ A converter but also a complementor, then the power and area cost of a traditional complementor is saved. 本文提出了一个新的DDFS改进设计方法,用一个有+/-控制的D/A转换器来同时实现D/A转换和补码器两者的功能,同时还能减省补码器所需的功耗和面积。