New Results with Oversampled Converters.

摘要

There has been a recent flurry of activity developing techniques which use DSP methods to exchange excess sample rate for improved resolution in analog-to-digital converters. These techniques use feedback around low-cost low-resolution quantizers, operating with excess sample rate, to shift the in-band quantizing noise power to out-of-band spectral regions from where it is removed by a resampling lowpass filter. An example of such a system is the multi-loop sigma-delta quantizer. Loops with multi-bit quantizers offer significant advantages over those with one-bit quantizers. Delays through the digital subsystems of the multi-bit quantizer limit conversion speed of the loop. We present an overview of the techniques which use multi-bit quantizers, identify important design limitations, and describe a number of methods to extend these limits. Keywords: Digital filter, Reprints, Computer hardware, Quantizers, Low-power filter, ADC, Analog-to-digital converters. (jg)