Patent ID: 8130323

Claim:
A video signal processing system comprising: a digital signal processing (DSP) module including a digital offset module; a gain module; and a digital to analog converter (DAC) coupled to the DSP module and to the gain module, wherein the DAC is configured to: cause the gain module to provide multiple gain control signals having predetermined first values to the DAC; cause, for each of the first values of the multiple gain control signals, a digital input signal value to the DAC to be ramped up; determine, for each of the first values of the multiple gain control signals, a lowest digital input signal value, in response to being ramped up, that causes an output voltage of the DAC to be at least as high as a reference voltage; and determine, based on the determined digital input signal values and corresponding first values of the multiple gain control signals, a second gain control signal value suitable for calibration of the DAC, such that the second gain control value causes the DAC to provide a desired DAC output voltage in response to the DAC receiving a reference DAC input value, wherein each pair of determined digital input signal value and corresponding first value of the multiple gain control signal defines a data point having a linear relationship with any of the other data points, wherein the DAC is configured to determine the second gain control signal value using interpolation of the data points.