Patent ID: 9130463
Filing Date: 2015-09-08
Classification: H02M,H03K

Abstract:
1. A drive circuit for a switching element, comprising: a constant-current control unit that performs a constant-current control for charging an open/close control terminal of a switching element to be driven which is a voltage-controlled switching element with electric charge for turning on the switching element; and a restriction unit that restricts, to a reference voltage, a voltage between the open/close control terminal and a first end of a pair of ends of a current flow path of the switching element for a predetermined period following a start of the constant-current control within a charging process period during which the open/close control terminal is charged with the electric charge such that the switching element is turned on; wherein: the restriction unit starts to restrict based on a condition that at least two physical quantities, following an input timing of a command for turning on the switching element, change in association with the command; the constant-current control unit includes a series connection of a constant-current resistor and a constant-current switching element which connected between the open/close control terminal and a direct current voltage source, and an operation unit that operates the open/close control terminal of the switching element such that an amount of voltage drop in the constant-current resistor is controlled to a target value, and the physical quantities include at least one of a voltage in the open/close control terminal of the switching element, an amount of voltage drop between both ends of the constant-current resistor, and a potential in an input terminal and an output terminal of the constant-current switching element.