Current cell matrix type digital-to-analog converter
AssigneeOki Electric Industry Co., Ltd.
InventorMasaru Sekiguchi
Life of this patent
Estimating the term…
Abstract
A converter 10 selects desired unit current cells from unit current cells 16, 18, 20, 22 in accordance with an input code 102, and supplies currents from the selected cells to a load resistor 24 to generate an analog voltage Vdac. By supplying the constant current comprised of the currents from the selected cells and currents from non-selected cells to an offset adjuster circuit 26 including an adjusting resister 28 to generate an offset voltage Vos, the converter 10 can output a voltage Vout which is the sum of the analog voltage Vdac and the offset voltage Vos.
Claims7
A current-cell matrix type digital-to-analog converter comprising:
- a plurality of unit current cells arranged in a matrix form, each being selected or non-selected in accordance with a digital signal;
- a first connection line supplied with a first current from all selected unit current cells of said plurality of unit current cells;
- and
- a first load resistor connected to said first connection line and supplied with the first current;
- wherein said converter includes:
- a second connection line supplied with a second current from all non-selected unit current cells of said plurality of unit current cells, said second current being an inverted output of the first current;
- and
- an offset adjuster circuit connected to said first connection line through a first load resistor and connected to said second connection line, wherein
- said offset adjuster circuit produces a constant voltage based on the first current supplied from said first connection line and a second current supplied from said second connection line irrespective of whether said plurality of unit current cells are selected or non-selected, to generate an offset voltage, and
- said converter outputs a first analog voltage signal based on a first potential generated across the first load resistance from the first current and said offset voltage.
Dependencies are inferred from the claim text.