A high-side transistor and a low-side transistor each has gate electrodes configured so as to allow signals to be input and output via a driving contact and a detection contact provided at different positions. When a control signal is at a first level and a signal output from the detection contact on the low-side transistor side is at a low level, the high-side driver applies a low-level signal to the driving contact on the high-side transistor side. When the control signal is at a second level and a signal output from the detection contact on the high-side transistor side is at a high level, the low-side driver applies a high-level signal to the driving contact on the low-side transistor side.