Patent ID: 8294433

Claim:
A constant current supply type switching regulator for generating a predefined constant current from an input voltage supplied to an input terminal and supplying the generated current from an output terminal, comprising: a switching element configured to activate a switch operation depending on an input control signal; an inductor configured to be charged with the input voltage in response to the switching element activating the switch operation; a rectification element configured to discharge the inductor in response to the switching element shifting to a cutoff state; a current detection circuit unit configured to generate a current proportional to a current flowing into the switching element from a voltage at a connection unit connecting the switching element with the rectification element and generate and supply a current sense voltage depending on the proportional current; and a control circuit unit configured to average the current sense voltage supplied from the current detection circuit unit and perform PWM (Pulse Width Modulation) control on the switching element for supplying a constant current in order to force the averaged voltage to be equal to a first reference voltage, wherein the control circuit unit integrates and averages the current sense voltage while the switching element is in a conducting state, compares the averaged voltage with the first reference voltage and uses a pulse signal indicative of the comparison to perform the PWM control for supplying the constant current.