Patent ID: 7423567
Filing Date: 2008-09-09
Classification: H03M

Abstract:
1. An analog-to-digital converter, comprising: an analog loop filter of second order or higher order and having an input for receiving an input signal of said analog-to-digital converter; a quantizer having an input coupled to an output of said loop filter, wherein said quantizer introduces quantization noise by quantizing said output of said loop filter; a digital integrator having an input coupled to a digital output of said quantizer; and a multi-bit digital-to-analog converter having an input coupled to an output of the digital integrator, wherein the multi-bit digital-to-analog converter provides a number of analog levels in excess of two as feedback to the analog loop filter corresponding to a first feedback signal path, whereby said loop filter frequency-shapes said quantization noise to move said quantization noise to a frequency band outside of a frequency band of said input signal of said analog-to-digital converter.