Patent ID: 9100041
Filing Date: 2015-08-04
Classification: H03M

Abstract:
1. A circuit for reduction of total harmonic distortion and noise in a multiple bit oversampling data conversion apparatus with limited code transitions between digital code words representing an instantaneous analog signal level, comprising: a most significant code word boundary comparator for determining if a previous data conversion code is equal to or greater than a most significant code word boundary; a least significant code word boundary comparator for determining if a previous data conversion code is equal to or less than a least significant code word boundary; and a code converter enabling circuit connected for generating and transferring an enabling/disabling signal to a plurality of code converter circuits within the multiple bit data bit oversampling data conversion circuit for enabling and disabling groups of the code converter circuits to reduce a capacitance loading on a delta-sigma modulator of the multiple bit oversampling data conversion apparatus to reduce the total harmonic distortion and noise in the multiple bit oversampling data conversion apparatus; wherein when the most significant word boundary comparator indicates that the previous data conversion code is equal to or greater than the most significant code word boundary, the group of code converters circuits designated to represent the most significant data bits of a current data conversion code are enabled and the group of code converter circuits designated to represent the least significant data bits of a current data conversion code are disabled; wherein when the least significant word boundary comparator indicates that the previous data conversion code is equal to or less than the least significant code word boundary, the group of code converters circuits designated to represent the least significant data bits of a current data conversion code are enabled and the group of code converter circuits designated to represent the most significant data bits of a current data conversion code are disabled.