A Nyquist-rate pipelined oversampling A/D converter

Oversampling and noise-shaping techniques, such as /spl Sigma//spl Delta/ modulation, have an inherent tradeoff between accuracy and speed, whereby resolution in amplitude is at the expense of resolution in time. Because their internal circuits must operate over many clock cycles to produce a single result, they have limited data rates and power dissipation is a concern. Much attention has been focused on improving the speed and power of /spl Sigma//spl Delta/ analog-to-digital converters (ADCs) by use of higher-order modulators, multi-bit feedback, and multi-bit architectures with single-bit feedback. However, data rates remain limited to less than a few MHz and are not easily extended. A pipelined oversampling architecture circumvents this speed-resolution tradeoff by performing spatial, rather than temporal, oversampling. It combines the high resolution of /spl Sigma//spl delta/ techniques with the high speed of pipelined converters so that both of these attributes are simultaneously achievable.