Patent ID: 7592940
Filing Date: 2009-09-22
Classification: H03M

Abstract:
1. A digital-to-analog converter, comprising: a coarse resistor-string digital-to-analog conversion unit for selectively outputting one of the 2 a fine resistor-string digital-to-analog conversion unit for selectively outputting one of the 2 a voltage combining unit including: a capacitor, a switching circuit configured to provide a plurality of capacitive couplings by switching the connection of first and second nodes of the capacitor, a coarse analog voltage terminal of the coarse resistor-string digital-to-analog conversion unit, a lowest reference voltage terminal; and a fine analog voltage terminal of the fine resistor-string digital-to-analog conversion unit and a unit gain buffer circuit configured to buffer a voltage generated by the capacitive coupling and output the 2 wherein the unit gain buffer circuit has a positive input terminal connected to the first node of the capacitor and a negative input terminal feedback-connected to an output terminal of the unit gain buffer circuit.