Pipeline direct digital frequency synthesiser using decomposition method

A direct digital frequency synthesiser using a new decomposition method wit hout the lame sine ROM table is presented. To improve its operating frequen cy a pipeline structure has been utilised. It has been fabricated in a 0.6 mum single-poly double-metal (SPDM) CMOS process and its core area is 0.95 x 1.1 mm(2). The maximum operating frequency is 85 MHz. For a 10 MHz sinuso idal output, the phase noise is -114dBc/H2 at an offset frequency of 10 kHz , The measured SNR is 60.77dB and worst case spurious is -67.6dBc, Its powe r dissipation is 80 mW at 80 MHz under the 5 V supply.