Patent ID: 8912782

Claim:
A direct current DC-to-DC converter adapted for generating a power voltage required by a load, and the DC-to-DC converter comprising: a buck circuit for receiving a DC input voltage, and performing a buck process to the DC input voltage according to a first control signal, the buck circuit includes an inductor having a first end coupled to a first switch and a first diode, and a second end outputting the power voltage or the DC input voltage; and a boost circuit coupled to the load and the buck circuit, the boost circuit is for receiving the power voltage or the DC input voltage output from the buck circuit, and performing a boost process to the DC input voltage output from the buck circuit according to a second control signal, the boost circuit includes a transformer only having a first terminal, a second terminal and a dotting terminal, the first terminal is coupled to the load through a second diode, the second terminal is coupled to a second switch and the dotting terminal is coupled between the second end of the inductor and the load through a third diode, wherein when the DC input voltage is higher than the power voltage required by the load, only the buck circuit performs the buck process to generate the power voltage, and the boost circuit directly transmits the power voltage to the load, wherein when the DC input voltage is lower than the power voltage required by the load, the buck circuit directly transmits the DC input voltage to the boost circuit, and only the boost circuit performs the boost process to generate the power voltage to the load.