Digital-to-analog converter and active matrix liquid crystal display

Abstract

A digital-to-analog converter includes a first converter stage 1 for converting the m most significant bits of a k bit input signal to upper and lower voltage limits VL and VH by selecting the appropriate low impedance reference voltages. A second converter stage 2 performs a linear conversion of the n least significant bits of the k bit input within the voltage range defined by the voltage limits VL and VH. A precharging circuit including switches SW1 and SW2 disconnects the stage 2 from the load CLOAD, which is charged to the voltage limit VL during the precharge phase. The load is subsequently disconnected from the voltage limit VL and connected to the output of the stage 2 to complete charging of the load CLOAD to the converter output voltage.

Dependencies are inferred from the claim text.