SYNCHRONOUS RECTIFYING TYPE SWITCHING REGULATOR, CONTROL CIRCUIT OF SYNCHRONOUS RECTIFYING TYPE SWITCHING REGULATOR, AND OPERATION CONTROL METHOD OF SYNCHRONOUS RECTIFYING TYPE SWITCHING REGULATOR

摘要

PPROBLEM TO BE SOLVED: To obtain a synchronous rectifying type switching regulator which has an inductor current not flowing reversely and can be set so that a time when a forward current applied to an inductor can be minimized in detecting a reversely flowing current, and to provide a control circuit of the synchronous type rectifying switching regulator, and an operation control method of the synchronous type rectifying switching regulator. PSOLUTION: In the synchronous rectifying type switching regulator, a reverse current detecting circuit 3 detects a forward current applied when an inductor L1 is discharged by a synchronous rectification transistor M2, and an offset voltage Voff is controlled to adjust timing for interrupting a current applied to the transistor M2 in order to prevent the generation of a reverse current, thereby enabling to adjust a time from the interruption of a current applied to the transistor M2 by turning off an NMOS transistor M3 to prevent the generation of the reverse current applied from an output terminal OUT to the direction of the transistor M2 until it is determined that the forward current becomes zero. PCOPYRIGHT: (C)2008,JPO&INPIT