Driving controller and full-bridge converting circuit

摘要

The present invention provides a full-bridge driving controller and a full-bridge converting circuit, which have the function of soft switch, to provide a DC output voltage. The present invention employs a resonant unit to oscillate the current flowing through the converting circuit at a resonant frequency. The full-bridge driving controller switches four full-bridge transistor switches at an operating frequency higher than the resonant frequency, so as to achieve the function of soft switch.

主权项

1. A full-bridge converting circuit, adapted to provide a DC output voltage, the full-bridge converting circuit comprising:
a resonant unit having a primary side and a secondary side; a first transistor switch coupled to an input power source and a first terminal of the primary side; a second transistor switch coupled to the first terminal of the primary side and a common potential; a third transistor switch coupled to the input power source and a second terminal of the primary side; a fourth transistor switch coupled to the second terminal of the primary side and the common potential; a rectification unit coupled to the secondary side of the resonant unit for rectifying power of the resonant unit to output the DC output voltage; and a full-bridge driving controller adapted to switch the first transistor switch, the second transistor switch, the third transistor switch and the fourth transistor switch at an operating frequency, thereby enabling the first transistor switch and the second transistor switch to be turned on at different time periods and the third transistor switch and the fourth transistor switch to be turned on at different time periods, wherein the operating frequency is higher than a resonant frequency of the resonant unit, wherein the full-bridge driving controller turns off one of the second transistor switch and the third transistor switch when a current flowing through the second transistor switch and the third transistor switch which are turned on is detected to be smaller than a preset current value.