Display driving circuit

摘要

A display driving circuit comprising a video signal transformation circuit, a reference voltage generating circuit, a DAC and an interpolation operational amplifier is provided. The video signal transformation circuit transforms an input video signal into a transformed video signal with a higher bit depth. The transformed video signal comprises an upper n bits data and a lower m bits data, wherein n+m equals a bit depth of the transformed video signal. The reference voltage generating circuit generates reference voltages. The DAC selects a first reference voltage and a second reference voltage to interpolation operational amplifier from the reference voltages according to an upper n bits data of the transformed video signal. The interpolation operational amplifier outputs a driving voltage to display device according to the first reference voltage, the second reference voltage and the lower m bits data of the transformed video signal.

主权项

1. A display driving circuit, comprising:
a video signal transformation circuit for transforming an input video signal into a transformed video signal with a higher bit depth which contains information of gamma correction according to a lookup table (LUT) or a digital interpolation technique, the transformed video signal with the higher bit depth comprises an upper n bits data and a lower m bits data, wherein n+m equals a bit depth of the transformed video signal and the bit depth of the transformed video signal is higher than that of the input video signal according to a lookup table (LUT) recording mapping relationships between a part of input video signal values and corresponding output signal values, and for calculating the corresponding output signal values for the input video signal values of which the mapping relationships are not recorded in the LUT; a reference voltage generating circuit for generating a plurality of reference voltages; a data latch coupled to the video signal transformation circuit; a level shifter coupled to the data latch; a digital to analog converter (DAC) for selecting a first reference voltage and a second reference voltage from the reference voltages generated by the reference voltage generating circuit, wherein the first reference voltage and the second reference voltage are selected according to the upper n bits data of the transformed video signal with the higher bit depthreceiving n bit data from the level shifter; and an interpolation operational amplifier for outputting a driving voltage corresponding to the transformed video signal with the higher bit depth according to the first reference voltage, the second reference voltage and the lower m bits data of the transformed video signal with the higher bit depthcoupled to the digital to analog converter and receiving m bit data from the level shifter for outputting a driving voltage, wherein n+m equals a bit depth of the transformed video signal.