Patent ID: 8848331
Filing Date: 2014-09-30
Classification: H03F

Abstract:
1. A protection device for protecting a protection-target switching element that includes a first terminal, a second terminal and a control terminal, the first terminal being connected to a first voltage line to which a first voltage is applied, the second terminal being connected to a second voltage line, to which a second voltage different from the first voltage is applied, and to an inductor having an inductor component, and the control terminal being applied with an off-voltage that changes a state between the first and second terminals, which are in a conduction state at a normal time, to a non-conduction state, the protection device comprising: a serial element unit that includes a switching element and a resistor series-connected to the switching element, the switching element being switchable from a non-conduction state to a conduction state according to a first control signal, one end of the serial element unit, which is connected to the control terminal of the protection-target switching element, being one end of the switching element or one end of the resistor, and the other end of the serial element unit, which is connected to the first voltage line, correspondingly being one end of the resistor or one end of the switching element; a capacitive load having a capacitance value that delays a transition of the protection-target switching element from the conduction state to the non-conduction state to thereby prevent a latch-up; and a controller that includes a first output terminal, which outputs, to the control terminal, the off-voltage that puts the protection-target switching element in the non-conduction state, and a second output terminal, which outputs the first signal that puts the switching element in the conduction state if an overcurrent flows through the protection-target switching element.