Title: Precision low noise-delta-sigma adc
Application Number: 200610126193 Application Date: 2006.09.07
Publication Number: 1929309 Publication Date: 2007.03.14
Approval Pub. Date: Granted Pub. Date:
International Classifi-cation: H03M1/08;H03M1/12;H03M3/02
Applicant(s) Name: Agilent Technologies Inc. Address:
Inventor(s) Name:
Attorney & Agent: wangyi
Abstract:
    A delta-sigma converter has coarse and fine ADCs, wherein an integrated error signal is coupled to the coarse ADC whose output drives a DAC to create feedback that achieves loop balance. The coarse ADC provides the most significant bits of the result. The integrated error signal is also applied to a fine ADC whose output bits are not incorporated into the feedback, but which are combined with those of the coarse ADC and the combination applied to a filter that averages the hunting that represents loop balance. A DC feed forward circuit shunts the integrator with a replica of the applied input signal to apply it to the coarse ADC through a summer, allowing its output to be just the integrated error signal without including the applied input.
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