Digital-to-analog converter based on a pre-decoder, a binary decoder and ROM decoders

摘要

For reducing device areas required by digital-to-analog converters used in source driving circuits of a liquid crystal display device, a compound circuit structure based on a pre-decoder, a binary decoder, and ROM decoders is set forth to meet the demand for cutting down the device areas. The pre-decoder is configured to decode a first sub-signal of a digital data signal for generating a plurality of control signals. Each of the ROM decoders is configured to select a gamma reference voltage out of one corresponding set of gamma reference voltages based on the control signals and a second sub-signal of the digital data signal. The binary decoder is configured to select one of the gamma reference voltages selected by the ROM decoders based on a third sub-signal of the digital data signal for outputting an output voltage. The number of transistors used by the compound circuit structure is then reduced significantly.