SYNCHRONOUS RECTIFICATION TYPE SWITCHING REGULATOR, CONTROL CIRCUIT OF THE SYNCHRONOUS RECTIFICATION TYPE SWITCHING REGULATOR, AND OPERATION CONTROL METHOD OF THE SYNCHRONOUS RECTIFICATION TYPE SWITCHING REGULATOR

摘要

PPROBLEM TO BE SOLVED: To provide a synchronous rectification type switching regulator which improves the efficiency, reducing reverse current at light load, and reduces the damping noise that affects the load, by preventing the generation of resonance, to provide a control circuit for the synchronous rectification type switching regulator, and to provide an operation control method of the synchronous rectification type switching regulator. PSOLUTION: When the voltage of a connection Lx1 becomes grounding voltage, and a sign that a reverse current will be generated is detected, and when the voltage of the connection Lx1 exceeds the grounding voltage and generation of the reverse current is detected, the switching regulator is constituted so that a low-level signal is output from a comparator 11, an AND circuit AN1 outputs the low-level signal, regardless of a pulse signal Spw input, and turns off a third switching element M3, only a second switching element M2 performs switching for synchronous rectifications, the on-resistance of the second switching element M2 is kept large, and the reverse current from an output terminal OUT to the grounding voltage is reduced. PCOPYRIGHT: (C)2007,JPO&INPIT