Sigma-delta oversampled analog-to-digital converte

专利名称：Sigma-delta oversampled analog-to-digital

converter network with chopperstabilization

发明人：David B. Ribner申请号：US07/645157申请日：19910124公开号：US05148167A公开日：19920915

摘要：In an oversampling interpolative analog-to-digital converter having a sigma-delta modulator followed in cascade by a decimation filter, the decimation filter suppliesdigital output signals for the oversampling analog-to-digital converter at an output ratethat is a submultiple 1/R of an oversampling rate at which digital samples of an inputsignal for said decimation filter are supplied. The chopping rate of the chopper-stabilized amplifier is a multiple of the output sample rate of the decimation filter toplace the fundamental and the harmonics of the chopping at the frequencies

corresponding to the zeroes in the decimation filter response, better to keep remnantsof the chopper stabilization from appearing in the output samples from the decimationfilter. The chopper stabilization moves the flicker (or 1/f) noise of the amplifier in thefrequency spectrum from baseband to sidebands of the chopping frequency, and thechopper-stabilized amplifier is operated at a chopping rate higher than said output rate,to reduce the amplitude of the lower sideband as aliased into the baseband. Thechopper-stabilized amplifier is operated at a chopping rate lower than half said

oversampling rate, to reduce non-linearities associated with the settling of the chopper

stabilized amplifier after each switching thereof.

申请人：GENERAL ELECTRIC COMPANY

代理人：Allen L. Limberg,James C. Davis, Jr.,Marvin Snyder

更多信息请下载全文后查看