The control circuit of the boost die switching generator regulator, being the control circuit of the boost die switching generator regulator which possesses the inductor where in the boost die

摘要

PROBLEM TO BE SOLVED: To provide a control circuit of a switching power supply in which a current can be detected with high precision.;SOLUTION: In the control circuit 100 of a switching power supply 200, a driver circuit 10 generates a drive signal Sd being supplied to the control terminal of a switching transistor M1 based on a pulse modulation signal Sp the duty ratio of which is controlled such that the output voltage Vout approaches a target voltage Vref. A threshold voltage source 22 generates a predetermined threshold voltage Vth1. The threshold voltage source 22 includes a reference transistor M2 of the same type as the switching transistor M1 and having a first terminal to which a fixed voltage GND is applied, and a constant current source 26 for supplying a predetermined constant current Ic1 to the reference transistor M2. Voltage at the joint of the reference transistor M2 and the constant current source 26 is applied to a comparator 24 as a threshold voltage Vth1.;COPYRIGHT: (C)2008,JPO&INPIT