Title: Current source cell arrangement and digital-to-analog converter
Application Number: 200610164727 Application Date: 2006.12.06
Publication Number: 1980069 Publication Date: 2007.06.13
Approval Pub. Date: Granted Pub. Date:
International Classifi-cation: H03M1/66;H03M1/06
Applicant(s) Name: NEC Electronics Corp. Address:
Inventor(s) Name: Shimaya Hiroshi
Attorney & Agent: lujin hua liya
Abstract:
    The object of the present invention is to form a highly accurate current source for DA converters. Letters from a1 to an where n is at least 4 represent current source cells that output constant currents, each of which is composed of MOS transistors etc. These current source cells are arranged in two dimensional matrix and a plurality of these current source cells are connected to form a current source that has a predetermined current value. Current source cells in any one row of the two dimensional matrix are labeled with letters from a1 to an. A first kind of row is in the same order as this row. A second kind of row is obtained from the first kind of row by exchanging a series of elements being letters from ai to ai j where both i and j are integers at least 1 and i j is an integer not more than n/2 with a series of elements being letters from ak to ak j where k is an integer larger than n/2 and k j is an integer not more than n. The two dimensional matrix comprises a same number of these two kinds of row.
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