A charging device that may perform charging with larger current is
provided. The charging device comprises a switching element for
increasing or decreasing charging power, a PWM controlling circuit for
intermittently turning the switching element on or off, a current
detecting circuit for detecting current flowing through the switching
element, and a rectifying circuit for rectifying output voltage of the
current detecting circuit in response to power supply voltage. The PWM
controlling circuit has a limiter terminal for turning off the switching
element when voltage equal to or above a determined value is input, and
rectified voltage from the rectifying circuit is input to the limiter
terminal. In this charging device, an amount of temperature increase of
the switching element is suppressed so as to remain within a fixed range,
and the charging power is not restricted unnecessarily.