According to one embodiment, a semiconductor device includes a first voltage generator, a second voltage generator, a first MOS transistor, and a controller. The first voltage generator outputs a first voltage to a first node. The second voltage generator outputs a second voltage to a second node. The first MOS transistor is capable of short-circuiting the first node and second node. The controller performs a control operation to short-circuit the first node and second node by turning on the first MOS transistor. The controller controls a period in which the first MOS transistor is kept in an on state based on time.