Patent ID: 6285309
Filing Date: 2001-09-04
Classification: H03M

Abstract:
A multi-stage analog-to-digital converter for converting an analog input signal to a series of digital values, each having a first plurality of bits, representing the voltage levels of said analog input signal at a corresponding series of sample times, comprising:a plurality of analog-to-digital converter stages connected serially in pipeline configuration, one or more of such stages comprising,a sample and hold amplifier, receiving an input signal, and holding for a predetermined period of time a voltage corresponding to the voltage levels of said input signal at said series of sample times, the first of said stages receiving said analog input signal, and subsequent stages in said pipeline receiving the output of the immediately preceding stage,an analog-to-digital subconverter, providing a second plurality of bits of said digital value, where said second plurality is smaller than said first plurality, said analog-to-digital subconverter being comprised of a plurality of analog-to-digital subconverter substages connected serially in pipeline configuration, each such subconverter substages providing one or more bits of said second plurality of bits,a digital-to-analog subconverter, converting said second plurality of bits to an analog value, anda difference circuit subtracting said intermediate analog value from said input signal, and providing the difference as a residue signal to the next one of said analog-to-digital converter stages in the pipeline.