Control circuit for synchronous rectifier-type DC-DC converter, synchronous rectifier-type DC-DC converter and control method thereof

Abstract

To provide a control circuit for a synchronous rectifier-type DC-DC converter, a synchronous rectifier-type DC-DC converter and a control method thereof in which, in a light load state and a no-load state, an output voltage can be dropped to thus prevent an overshoot state from continuing. A synchronous rectifier-type DC-DC converter 10 and a control circuit 20A thereof comprising a first switching element FET1 that is made conductive when power is accumulated in an induction element L1, and a second switching element FET2 that is made conductive when power accumulated in induction element L1 is supplied to a load, also comprises a detecting unit COMP2 that detects that a value of an output voltage VOUT of the synchronous rectifier-type DC-DC converter 10A is a predetermined voltage value that is higher than a target voltage value, and control units COMP1 and OR1 that maintain the second switching element FET2 in a conductive state after discharge of the power accumulated in the induction element L1 is finished, based on the detection results of the detecting unit COMP2.

Dependencies are inferred from the claim text.