| 摘要 |
PROBLEM TO BE SOLVED: To provide a control circuit switching between a single channel output mode and a multi-channel output mode. SOLUTION: When a two-channel switching regulator using a diode rectification system is to be controlled, a control circuit 100 is set in a first mode. When a single-channel step-down switching regulator using a synchronous rectification system is to be controlled, a second mode is set.In the first mode, output signals Sd1 and Sd2 of drivers DRV1 and DRV2 are supplied to high-side transistors of the two-channel switching regulator. In the second mode, the output signal Sd1 of the first driver DRV1 is supplied to the high-side transistor of the switching regulator. A duty ratio of the output signal Sd2 of the second driver DRV2 is set to a value corresponding to first feedback voltage Vfb1, and the signal is supplied to a low-side transistor of the switching regulator. COPYRIGHT: (C)2009,JPO&INPIT
|
