Trim digital-to-analog converter (dac) for an r2r ladder dac

Abstract

A digital-to-analog converter (DAC) includes a first stage comprising a plurality of first circuit arms coupled together, each first circuit arm including a resistor. A second stage includes a plurality of second circuit arms coupled together, each second circuit arm comprising a first resistor and a pair of series-connected resistors. The first resistors of the second circuit arms are connected in series. A current digital-to-analog converter (IDAC) trim circuit is connected to a plurality, but not all, of the second circuit arms of the second stage. The IDAC trim circuit includes a plurality of first current sources. Each first current source is coupled to a respective node between a pair of the series-connected resistors of a corresponding second circuit arm, and each of the first current sources is configured to produce a same current level as the other first current sources.