Patent ID: 8581897

Claim:
A DC-DC converter for generating a first voltage and a second voltage lower than the first voltage, the DC-DC converter being coupled to a display unit and comprising: a first voltage generator for generating the first voltage by switching an input voltage and accumulating energy in a first coil; a second voltage generator for generating the second voltage by switching the input voltage and accumulating energy in a second coil; a pulse width modulation (PWM) controller for controlling switching times of the first and second voltage generators in accordance with a control signal; and a voltage adjuster for generating the control signal based on a luminance or an image display area of the display unit to vary a voltage level of the second voltage and control a time of change of the second voltage, wherein a time period for a data signal is divided into a data blanking period and a data display period, and wherein the voltage adjuster is configured to control the time of change of the second voltage by generating the control signal to vary the voltage level of the second voltage during the data blanking period.