Apparatus for and method of performing a conversion operation

In a self-calibrated current cell that operates in a calibration state, a supplying state, and a dumping state, wherein the current cell comprises a capacitor storing a reference current in the calibration state, the stored current in the capacitor is dumped to ground in the dumping state, and the stored current is steered to an output load in the supplying state, a method of operating the self-calibrated current cell comprising the steps of:

• (a) applying a dumping control signal to the current cell to place the current cell in the dumping state;
• (b) applying a calibration control signal to the current cell to place the current cell in a calibration state;
• (c) releasing the calibration control signal to return the current cell to the dumping state;
• and
• (d) placing the current cell in a supplying state.

A converter comprising:

• a first controller issuing a first control signal;
• a second controller issuing a second control signal;
• and
• a cell array receiving control signals from said first controller and said second controller, wherein individual first control and second control signals issued respectively by said first and second controllers sequentially place individual ones of a plurality of cells of said cell array in a calibration mode during a conversion operation of the converter.

A digital-to-analog converter comprising:

• a single-pulse generator, wherein said single-pulse generator periodically issues single pulses;
• a bit counter, coupled to said single-pulse generator, wherein said bit counter increments a stored count in response to single pulses received from said single-pulse generator;
• a bit shifter, coupled to said bit counter, wherein said bit shifter contains a plurality of shift registers shifting their respective contents based on the stored count received from said bit counter;
• a dump control register module, coupled to said bit shifter, containing a plurality of dump control registers;
• a calibration control register module, coupled to said bit shifter, containing a plurality of calibration control registers;
• and
• a current cell array receiving control signals from said dump control register module and said calibration control register module, wherein individual dump control and calibration control registers cooperate together to place individual ones of a plurality of current cells of said current cell array in a redundant calibration mode during a conversion operation of the digital-to-analog converter.