Mismatch shaping apparatus and method for binary coded digital-to-analog converters

A method comprising:

• receiving an N-bit digital input;
• encoding the N-bit digital input to generate an encoded (N+1)-bit digital output;
• and
• providing the encoded (N+1)-bit digital output to a digital-to-analog converter, wherein the encoded (N+1)-bit digital output is to shape mismatch errors in the digital-to-analog converter.

A method for converting a N-bit binary coded input digital signal into an analog output signal, the method comprising:

• accumulating a positive or negative usage of an individual digital-to-analog converter element to generate an accumulated positive or negative usage;
• encoding an individual digital bit, of the N-bit binary coded input digital signal, with a normal scheme or an alternate scheme depending on the accumulated positive or negative usage, such that through negative feedback, an accumulated error contributed from the individual digital bit is bounded close to zero;
• and
• providing the individual digital bit, which is encoded, to an (N+1)-bit binary weighted digital-to-analog converter which converts an (N+1)-bit digital signal into the analog output signal, wherein the (N+1)-bit binary weighted digital-to-analog converter includes the individual digital-to-analog converter element.

A method for shaping mismatch errors in a digital-to-analog converter, the method comprising:

• storing an accumulated digital value associated with an output bit;
• selecting an encoding scheme for an input bit based on the accumulated digital value to reduce the accumulated digital value to zero;
• generating an encoded digital value based on the encoding scheme;
• and
• applying the encoded digital value to the digital-to-analog converter having the mismatch errors such that the mismatch errors are shaped in frequency domain.