Method and apparatus for reducing capacitor induced isi in dacs

A digital-to-analog (DAC) element, comprising:

• a first current source;
• a second current source;
• a first set of switches arranged to form a plurality of primary circuit branches between the first and the second current sources, wherein:
• a first of the primary circuit branches includes a first switch connected between the first current source and a first output terminal, and a second switch connected between the second current source and the first output terminal,
• a second of the primary circuit branches includes a third switch connected between the first current source and a second output terminal, and a fourth switch connected between the second current source and the second output terminal;
• and
• a second set of switches arranged to form a plurality of corrective circuit branches between the first and the second output terminals, wherein:
• a first of the corrective circuit branches includes a fifth switch and a sixth switch connected in series between the first and the second output terminals, and
• a second of the corrective circuit branches includes a seventh switch and an eighth switch connected in series between the first and the second output terminals.

A digital-to-analog (DAC) element, comprising:

• a first resistor coupled to a first reference voltage;
• a second resistor coupled to a second reference voltage;
• a first set of switches arranged to form a plurality of primary circuit branches between the first and the second resistors, wherein:
• a first of the primary circuit branches includes a first switch connected between the first resistor and a first output terminal, and a second switch connected between the second resistor and the first output terminal,
• a second of the primary circuit branches includes a third switch connected between the first resistor and a second output terminal, and a fourth switch connected between the second resistor and the second output terminal;
• and
• a second set of switches arranged to form a plurality of corrective circuit branches between the first and the second output terminals, wherein:
• a first of the corrective circuit branches includes a fifth switch and a sixth switch connected in series between the first and the second output terminals, and
• a second of the corrective circuit branches includes a seventh switch and an eighth switch connected in series between the first and the second output terminals.

A method comprising:

• receiving a digital input signal at an input;
• switching each of a plurality of primary DAC elements between a first state and a second state based on the digital input signal to convert the digital input signal into an analog output signal;
• outputting the analog output signal to an output;
• and
• switching each of a plurality of corrective DAC elements between the first state and the second state such that a charge drawn from the output by parasitic capacitances of the main and corrective DAC elements is substantially constant,
• wherein the plurality of primary DAC elements are provided in parallel to the plurality of corrective DAC elements between the input and output.