Noise-shaped multibit D/A convertor employing unit elements

By appropriately selecting the elements used to form each output sample of a multibit digital-to-analogue convertor, the spectrum of the error caused by element mismatch can be noise-shaped. Simulations indicate that first-order, second-order and bandpass noise-shaping are all possible. The technique enables the use of multibit feedback in delta-sigma A/D and D/A convertors