Abstract: A DC-DC converter including, an inductor; and a driving switching element for performing switching to a flow path to flow an electric current through the inductor; wherein the DC-DC converter drives the driving switching element by PWM control using a PWM control pulse to convert a direct-current input voltage supplied from a direct-current power source and to output a direct-current voltage having a piece of electric potential different from that of the direct-current input voltage, and wherein the DC-DC converter drives the driving switching element by the PWM control under a first condition, and the DC-DC converter makes the driving switching element be in an on-state continuously while the output direct-current voltage is lower than a desired level under a second condition.

Abstract: A DC/DC-converter semiconductor integrated circuit using a bootstrap circuit includes a protection device having a standard breakdown voltage to break down between a first terminal and a second terminal, between which a capacitor of the bootstrap circuit is located, in response to a voltage higher than a maximum voltage applied to the capacitor.

Abstract: A DC-DC converter including, an inductor; and a driving switching element for performing switching to a flow path to flow an electric current through the inductor; wherein the DC-DC converter drives the driving switching element by PWM control using a PWM control pulse to convert a direct-current input voltage supplied from a direct-current power source and to output a direct-current voltage having a piece of electric potential different from that of the direct-current input voltage, and wherein the DC-DC converter drives the driving switching element by the PWM control under a first condition, and the DC-DC converter makes the driving switching element be in an on-state continuously while the output direct-current voltage is lower than a desired level under a second condition.