Patent ID: 7091753
Filing Date: 2006-08-15
Classification: H02M,H03K

Abstract:
1. A gate driving circuit comprising: a driving element unit comprising an ON-driving element serving as a switching element for applying an ON-voltage to a gate of a driving target device serving as a switching element so that the driving target device is set to ON-state, and an OFF-driving element serving as a switching element for applying an OFF-voltage to the gate of the driving target device so that the driving target device is set to OFF-state, the ON-driving element and the OFF-driving element being connected to each other in series and the gate of the driving target device being connected to a connection point between the ON-driving element and the OFF-driving element; an auxiliary driving unit having a composite element comprising a reactor and an auxiliary driving element serving as a switching element for controlling current flowing in the reactor, the reactor and the auxiliary driving element being connected to each other in series, and one terminal of the composite element being connected to a connection point between the ON-driving element and the OFF-driving element while the other terminal of the composite element is connected to a driving power source terminal; and a driving control unit for: turning on the auxiliary driving element to make current flow into the reactor when the driving target device is turned off under a state that only the ON-driving element of the driving element portion is turned on; turning on the auxiliary driving element to make current flowing into the reactor when the driving target device is turned on under a state that only the OFF-driving element of the driving element portion is turned on; turning off both the ON-driving element and the OFF-driving element constituting the driving element unit, inducing resonance by parasitic capacitance of the gate of the driving target device and the reactor; and turning on one of both the elements constituting the driving element unit and then turning on the other element when the gate voltage of the driving target element reaches an ON-voltage or OFF-voltage.