Patent ID: 8294434

Claim:
A constant current output control type switching regulator that creates a predetermined constant current from an input voltage inputted to an input terminal and outputs an output current from an output terminal, comprising: a switching element that executes switching according to an inputted control signal; an inductor that is charged by said input voltage due to the switching of the switching element; a rectifier element that discharges said inductor when the switching element is off and is in a cut-off state; a current detection circuit section that creates a proportional current proportional to a current running in said switching element, and creates and outputs a current sense voltage according to the proportional current; and a control circuit section that executes PWM control to control a constant current output of said switching element so that the current sense voltage of the current detection circuit section is equal to a second reference voltage, wherein said control circuit section creates an adjustment reference voltage by adjusting a predetermined first reference voltage according to the proportion of the output voltage that is the voltage of said output terminal and said input voltage, creates said second reference voltage by adding the voltage difference of the adjustment reference voltage and said current sense voltage to the adjustment reference voltage, creates a pulse signal representing a result of voltage comparison between said current sense voltage and said second reference voltage, and controls switching operation of the switching element by the PWM control based on said pulse signal.