Skip to Main Content
A ROM size reduction technique based on a new sine-amplitude approximation with small ROM size for direct digital frequency synthesizers is presented. With use of the proposed multiple trigonometric approximation for 12-bit phase to 10-bit amplitude mapping, the number of ROM output bits and ROM size are reduced by 5 and 44.45%, respectively, compared to the quarter sine wave technique, with comparable spectral purity. The proposed approach is also applied to a ROM segmentation method for further ROM size reduction, which has a compression ratio of 55:1.
Date of Conference: 4-8 Jan. 2003