Patent ID: 7075275

Claim:
A DC-DC converter comprising: switching means which receives an input voltage and generates a continuous switching voltage having a specified period from the input voltage; output voltage generating means which receives the switching voltage from the switching means at an inductor and generates an output voltage obtained by rectifying and smoothing a voltage generated in the inductor; lamp signal generating means which generates a lamp signal and outputs the generated lamp signal; and control means which performs an arithmetic operation using a current signal relative to a current flowing in the inductor, an error signal relative to the output voltage, and the lamp signal from the lamp signal generating means to generate a control signal for controlling an operation of the switching means and outputs the generated control signal to the switching means, wherein the lamp signal generating means includes: first signal generating means for generating a first output signal based on a frequency divided signal having first and second periods obtained by dividing a frequency of a clock signal having the specified period; and second signal generating means for generating a second output signal having a phase 180 degrees different from a phase of the first output signal based on the frequency divided signal, generates, based on the first and second outputs signals, the lamp signal which rises after being held at a constant value for a specified time period in each of the first and second periods, and outputs the generated lamp signal.