Patent ID: 7683590
Filing Date: 2010-03-23
Classification: H02M

Abstract:
1. A step-down switching DC-DC converter comprising: a power source; an input coil placed on an input side; an output coil placed on an output side; a switch turning on to establish a connection between the input coil and the output coil, and turning off to disconnect the connection between the input coil and the output coil; an output capacitor smoothing an output voltage; a first series circuit connected in parallel between a connection point, on which the input coil and the switch are connected to each other, and a negative pole of the power source, the first series circuit including a first intermediate capacitor and a first intermediate coil; and a second series circuit connected in parallel between a connection point, on which the output coil and the switch are connected to each other, and the negative pole of the power source, the second series circuit including a second intermediate capacitor and a second intermediate coil, wherein a connection point, on which the first intermediate capacitor and the first intermediate coil are connected to each other, is connected to a connection point, on which the second intermediate capacitor and the switch are connected to each other, via a switching device cooperating with the switch to complementarily turn on and off, and wherein the input coil and the first intermediate coil are electromagnetically coupled with each other, and the output coil and the second intermediate coil are electromagnetically coupled with each other.