Gate driving circuit
AssigneeDenso Corporation
InventorRyousuke Inoshita
Life of this patent
Estimating the term…
Abstract
In a gate driving circuit, when a driving target device is turned on, an auxiliary driving element is turned on to form a closed circuit comprising a DC power source, a reactor, an auxiliary driving element and an OFF-driving element, and make reactor current flow in the direction from a power source intermediate point to an output point in advance. Just before the driving target device is turned on, the OFF-driving element is turned off to form a resonance circuit comprising the reactor, the auxiliary driving element and the gate capacitance, and make gate current (reactor current) flow so that the gate capacitance is charged by using resonance phenomenon of the resonance circuit.
Claims7
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.
Dependencies are inferred from the claim text.