Display driver and semiconductor device

A semiconductor device comprising a display driver that drives a display device comprising first to Nth data lines, wherein N is an integer equal to or more than 2, the semiconductor device comprising:

• a data fetching unit that receives first to Nth pixel data pieces indicating luminance levels based on a video signal for each pixel and outputs the first to Nth pixel data pieces at a timing of an edge of a clock signal;
• a gradation voltage generation unit that converts the first to Nth pixel data pieces output from the data fetching unit into first to Nth gradation voltages;
• first to Nth amplifiers that supply first to Nth driving voltages obtained by amplifying the first to Nth gradation voltages to the first to Nth data lines;
• and
• a bias voltage generation unit that generates bias voltages for setting current values of operation currents of the first to Nth amplifiers and supplies the bias voltages to the first to Nth amplifiers,
• wherein the bias voltage generation unit comprises a register that stores first information indicating a first voltage value that is a voltage value of the bias voltage for setting a current value of the operation current to a first current value and second information indicating a second voltage value that is a voltage value of the bias voltage for setting the current value of the operation current to a second current value lower than the first current value, and
• the bias voltage generation unit generates the bias voltage having the first voltage value indicated by the first information during a period from a time point of the edge of the clock signal to a time point at which a first period has elapsed, and switches the voltage value of the bias voltage to the second voltage value indicated by the second information at the time point at which the first period has elapsed.