Title :
A low-complexity direct digital frequency synthesizer
Author :
Lin-Hui, Lai ; Xiao-Jin, Li ; Zong-sheng, Lai
Author_Institution :
Inst. of Microelectron. Circuit & Syst., East China Normal Univ., Shanghai, China
Abstract :
The traditional direct digital frequency synthesizer (DDFS) based on a lookup table has very high complexity. This paper describes a low complexity DDFS using smaller lookup table and with minimum additional hardware. The lookup table for sine/cosine functions is split into a coarse-precision ROM and a fine-precision ROM. Approximation of fine-precision ROM and application of shift registers are introduced to further reduce the hardware complexity. The implemental results show that the total size of ROM in this proposed DDFS architecture is only 328 bits compared with 448 bits , and the spectral purity can be as good as 63.58 dBc.
Keywords :
direct digital synthesis; read-only storage; shift registers; table lookup; DDFS; coarse-precision ROM; fine-precision ROM; hardware complexity reduction; lookup table; low-complexity direct digital frequency synthesizer; shift registers; sine/cosine functions; spectral purity; Clocks; Digital communication; Frequency control; Frequency synthesizers; Hardware; Microelectronics; Phase locked loops; Read only memory; Shift registers; Table lookup; digital communications; direct digital frequency synthesis (DDFS); low-complexity; spectral purity;
Conference_Titel :
Solid-State and Integrated-Circuit Technology, 2008. ICSICT 2008. 9th International Conference on
Conference_Location :
Beijing
Print_ISBN :
978-1-4244-2185-5
Electronic_ISBN :
978-1-4244-2186-2
DOI :
10.1109/ICSICT.2008.4734868
