/spl Delta/-/spl Sigma/ frequency-to-time conversion by triangularly weighted ZC counter

Abstract

We have shown that by introducing a triangular window in the traditional /spl Delta/-/spl Sigma/ counting FDC, /spl Delta/-/spl Sigma/ noise-shaping and decimation results. A simple way to implement the windowing function is by using a double module counter or a sinc/sup 2/ decimator. By in this way using a /spl Delta/-/spl Sigma/ decimator as a /spl Delta/-/spl Sigma/ counting FDC a higher digital resolution can be achieved than by using a standard count-and-dump FDC as the quantization error is noise-shaped.