Stacked digital-to-analog converter and methods of performing digital-to-analog conversion

A method of performing digital-to-analog conversion on M-bit samples to produce an analog signal having a fullscale comprising:

• defining the fullscale to have a plurality K of analog subranges, where K>=2;
• defining for each analog subrange a corresponding digital subrange of 0 to 2M−1;
• converting an M-bit digital sample into K digital samples, one for each subrange;
• performing a digital-to-analog conversion on each of said K digital samples to produce a respective analog signal;
• applying a respective gain adjustment to each of said analog signals so as to result in an analog signal having a dynamic range equal to the analog subrange corresponding with the analog signal's digital sample's digital subrange;
• and
• adding together all of the gain adjusted analog signals.

A digital-to-analog converting apparatus for performing a digital-to-analog conversion on M-bit samples to produce an analog signal having a fullscale, the apparatus comprising:

• digital sample splitting circuitry for converting an M-bit digital sample into K digital samples, one for each of a plurality K of digital subranges of 0 to 2M−1, where k is an integer ≧2.
• K digital-to-analog converters, for performing a digital-to-analog conversion on each of said K digital samples to produce a respective analog signal;
• gain adjustment circuitry for applying a respective gain adjustment to at least one of said analog signals so as to result in each analog signal having a respective dynamic range equal to an analog subrange of the fullscale which corresponds with the analog signal's digital sample's digital subrange;
• and
• adding circuitry for adding together all of the gain adjusted analog signals.

A digital-to-analog converting apparatus comprising:

• digital sample splitting means for producing K digital samples from an input M-bit sample, one for each of a plurality K of digital subranges of 0 to 2M−1;
• digital-to-analog conversion means for performing a digital-to-analog conversion on each of said K digital samples to produce a respective analog signal;
• and
• level-conversion means for converting a respective analog range of each analog signal to another respective analog range which is in correspondence with the analog signal's respective digital sample's digital subrange.