Patent ID: 9602126
Date: 2017-03-21
CPC Classifications: H03F,H03M

Claim:
1. A sigma-delta analog-to-digital converter (ADC), comprising: a first forward path connected to an input of the sigma-delta ADC comprising a filtering stage and a quantization stage, the first forward path having a transfer function H a first feedback path from an output of the first forward path to the input of the sigma-delta ADC, said first feedback path comprising a digital-to-analog converter (DAC) and a digital filter for converting the output of the first forward path, said first feedback path having a transfer function H wherein the sigma-delta ADC has a stable noise transfer function NTF given by: wherein H is the loop transfer function, said NTF having at least one damped zero; wherein, if H comprises undamped poles, H wherein the first feedback path comprises a finite impulse response (FIR) digital filter that has an impulse response that approximates the impulse response associated with H wherein the FIR digital filter is combined with the DAC for forming a finite impulse response digital-to-analog converter FIRDAC.