Patent ID: 6549196
Filing Date: 2003-04-15
Classification: G09G,H03M

Abstract:
A D/A conversion circuit provided with an analog reference power supply for using a first power supply voltage as a drive voltage and outputting a plurality of different voltages,a voltage selecting circuit configured to select one of said plurality of different voltages based on a string of digital data, and an output buffer configured to convert impedance of the voltage selected by said voltage selecting circuit, comprising: a charging/discharging voltage generating circuit configured to use a second power supply voltage as the drive voltage and to output a second power supply voltage correlated with said one of said plurality of different voltages of said analog reference power supply; and a current switchover circuit configured to switch a direction in which a current flows in such a manner that a charging/discharging current of an input parasitic capacitor of said output buffer passes through said charging/discharging voltage generating circuit for a predetermined period after said bit string of digital data changes, and in such a manner that said charging/discharging current passes through said analog reference power supply after said predetermined period elapses.