CONTROL CIRCUIT AND CONTROL METHOD

摘要

PROBLEM TO BE SOLVED: To improve setting accuracy of an output voltage.SOLUTION: A detection circuit 19 generates a control voltage Vb1 according to a comparison result between a current I14 according to an output current I12 of a differential circuit 11 and a current I15 of a current source 24. A current source 21 of the differential circuit 11 passes a current I11 according to the control voltage Vb1. The differential circuit 11 splits the current I11 flowing through the current source 21 according to differential voltage between an output voltage Vo and a reference voltage Vr1 to generate the output current I12. A current mirror circuit 12 generates a charging current Ip1 according to the output current I12 of the differential circuit 11. A charging circuit 13 charges a capacitor Cp1 through the charging current Ip1. By the charge of the capacitor Cp1, a ramp voltage Vp1 that changes at a rate (time constant) according to the output current I12 is generated. A transistor T1 is controlled by a comparison result between the ramp voltage Vp1 and the reference voltage Vc1.