Patent ID: 8836562

Claim:
A primary voltage divider of a dual-string digital-to-analog converter (DAC), comprising: a primary resistor string having a total resistance, the primary resistor string comprising a plurality of resistor nodes configured to divide a DAC input voltage applied across the primary resistor string into a plurality of divided voltage levels; a primary switch unit configured to receive a DAC input code and select a resistor node circuit among a plurality of resistor node circuits, the resistor node circuit comprising a selected resistor node pair among the plurality of resistor nodes of the primary resistor string based on the DAC input code to couple a divided voltage level across the selected resistor node pair to a secondary voltage divider circuit of a dual-string DAC; and at least one adjusting circuit comprising at least one first fractional resistance configured to adjust a resistance of the selected resistor node pair to maintain an ideal voltage of the selected resistor node pair across the secondary voltage divider circuit in response to the primary switch unit selecting the selected resistor node pair, without impedance isolation between the primary resistor string and the secondary voltage divider circuit.