A device is applicable to a display driver, including a sampling circuit and a logic circuit. The sampling circuit is configured to sample a command signal by recording a plurality of command values of the command signal at different times. The plurality of command values corresponds to at least one data line of a pixel circuit. The logic circuit is electrically coupled to the sampling circuit, and is configured to receive the plurality of command values. The logic circuit is further configured to generate a filtered command signal according to the plurality of command values, and is configured to provide the filtered command signal to drive the pixel circuit.