| 摘要 |
Analogue signals at input i/p are converted to digital data at output o/p by means of a Sigma-Delta modulator comprising a pair of bandpass filters consisting of an inductor L and a capacitor C in parallel and a feedback loop by means of which pulses generated by current generator I1 are dependent on the output of comparator Q. A correction feedback loop is provided by means of which correction pulses from current generator I2 are fed to the intermediate filter in response to the comparator output. The tendency of the analogue-to-digital converter to instability and the crosstalk between quadrature components of the input i/p are reduced or eliminated by the correction feedback loop. Further corrections may be provided via the correction feedback loop (fig 3). <IMAGE>
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