This paper presents comparisons of various DeltaSigma modulations in direct digital frequency synthesis. DeltaSigma modulators such as MASH, feedforward, feedback and error feedback have been implemented in both phase and frequency domains in a CMOS DDS. The DDS prototype is fabricated in a 0.35mum CMOS technology with core area of 1.7times2.1 mm and total 75 mA current. Measured DDS output demonstrates that frequency domain DeltaSigma modulation achieves better SFDR and SINAD than phase domain AE modulation
Published in:
Custom Integrated Circuits Conference, 2006. CICC '06. IEEE
Date of Conference: 10-13 Sept. 2006