Patent ID: 7609042
Filing Date: 2009-10-27
Classification: H02M,Y02B

Abstract:
1. A DC-DC converter for generating output voltage from input voltage, the DC-DC converter comprising: a first output transistor; a second output transistor electrically connected in series to the first output transistor; a choke coil electrically connected to a node between the first output transistor and the second output transistor with at least either one of the first output transistor and the second output transistor being operated to generate the output voltage of the DC-DC converter based on the input voltage; a smoothing capacitor, electrically connected to the choke coil, for smoothing the output voltage of the DC-DC converter; and a controller, electrically connected to the first output transistor and the second output transistor, for controlling the first output transistor and the second output transistor in a first operation mode or a second operation mode based on the output voltage of the DC-DC converter or output current, in which the output current changes in accordance with the output voltage, wherein the controller includes an error amplifier which generates a first error signal based on a differential voltage between the output voltage and a first reference voltage and a second error signal that is complementary to the first error signal, and wherein the controller activates and inactivates the first output transistor and the second output transistor in a complementary manner by a control signal in accordance with the first error signal during the first operation mode, and the controller inactivates the second output transistor and performs linear operation with the first output transistor by the second error signal during the second operation mode.