Patent ID: 6344812
Filing Date: 2002-02-05
Classification: H03M

Abstract:
A delta sigma digital-to-analog converter comprising:set of N one bit local digital to analog converters equally weighted to each other, where N is equal to P times Q and where P and Q are each predetermined integers having a value of at least two; a quantizer having a digital input and an output having P times Q minus one quantized levels at a predetermined sampling frequency fs; a first converter having an input connected to said output of said quantizer for converting said quantizer output to a thermometer code comprising P times Q bits, which thermometer code is provided as an output of said first converter; and a second converter connected to said output of said first converter for receiving said thermometer code, dividing a bit arrangement of said thermometer code into P blocks, each being taken as one block for every Q bits, shifting the bit arrangement in unit of the block in rotation at the sampling frequency fs, further shifting the bit arrangement in unit of the bit in rotation at the sampling frequency fs times Q, and thereby producing an output code on an output of said second converter, which output is, in turn, connected to said local digital to analog converters in corresponding order.