Digitally controlled voltage generator

摘要

A digitally controlled voltage generator is disclosed for use in applications requiring fine resolution voltage control, such as generating a common voltage for a liquid crystal display. A constant resistance digital to analog converter (DAC) is configured to provide appropriate voltage steps by tuning bias resistors to generate desirable reference voltages for the DAC. The bias resistors are configured to be tuned after placement and routing steps in an integrated circuit design.

主权项

1. An LCD display device comprising:
a plurality of LCD elements to which is supplied a common voltage reference; and a common voltage reference generator including a constant resistance digital-to-analog converter having a resistor network for generating an output voltage from which the common voltage reference is generated, wherein the common voltage reference generator further includes a resistor divider including a first resistor and a second resistor connected in series between an analog reference voltage and ground, a third resistor connected at a first end to a node between the first resistor and the second resistor and at a second end to the constant resistance digital-to-analog convertor, and a fourth resistor connected in series between the constant resistance digital-to-analog converter and ground.