Patent ID: 7064699
Filing Date: 2006-06-20
Classification: H03M

Abstract:
1. 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.