Circuit for PCM conversion of an analog signal, with improvement in gain- tracking

摘要

The circuit includes a filter to which an analog signal is applied, a quantizer driven by the filter, a sampler at a desired frequency driven by the quantizer and a PCM encoder driven by the sampler. The quantizer generates a quantize signal according to the received analog signal and further generates a difference signal according to the difference between a quantized signal and the analog signal. A feedback circuit feeds back the difference signal from the quantizer to a stage of the filter so that the overall transfer function from the input of the feedback circuit to the output of the filter is equivalent to a low pass filtering.