| Multi-stage delta-sigma (DeltaSigma) architectures, commonly known as MASH, are the preferred choice for analog-to-digital converters (ADCs) used in broadband communication applications, where high-resolution (above 14 bits) and high-bandwidth (several MHz) performances are required. Current state-of-the-art designs are capable of as much as 5-MS/s output data rates with 90-dB SNR. However, inherent limitations in this type of converters have been addressed by the use of high-quality analog circuit components, making designs more complex, less robust, and higher performances difficult to achieve.; This thesis describes the problems of extending bandwidth without losing accuracy in DeltaSigma A/D converters, and presents three techniques which can overcome these problems: a low-distortion analog signal processing technique, the digital adaptive correction of analog circuit imperfections, and the fully digital estimation and correction of DAC errors. Combined, these techniques have the potential to achieve high-speed, high-resolution wideband DeltaSigma conversion, even with low-performance analog components.; The presented techniques were combined in a prototype chip, designed and fabricated in a 0.18 mum CMOS process. Simulation and preliminary measurement results show that they are highly effective. |
