Apparatus for converting data between analog and digital values

Abstract

Signals representing individual digital values are introduced to pluralities of switches of corresponding digital significance to provide for the conductivity of an individual one of the switches in each pair in accordance with the digital value represented by such signals. A plurality of conductive output members to provide paths through a matrix relationship of the switches and through the output members to one of two output lines. This matrix provides for progressive increases in the number of the output members connected to a particular one of the output lines with progressive increases in the digital value and for a continued connection to the particular output line of output members previously connected to the particular output line with such progressive increases in the digital value. The cumulative current through the particular output line is indicative of the analog value. The output members are disposed on an integrated circuit chip in groups each having a common centroid arrangement to offset correlated errors in the output members in the group. The members in each group may be disposed in pairs relative to the common centroid to provide offsets in the correlated errors in the output members in each pair. The output members in the groups having intermediate digital values in the range of digital values may be disposed relative to the common centroid in positions providing minimum correlation errors. Coincidentally, the output members in groups having extreme digital values in the range of digital values may be disposed relative to the common centroid in positions providing increased correlation errors.