A driving circuit according to an embodiment includes a driving unit, a first temperature detecting unit, an overheat protecting unit, a second temperature detecting unit, and a failure diagnosing unit. The driving unit supplies a driving current to a load based on a control signal input from a controller. The overheat protecting unit blocks supply of the driving current to the load when the level of the signal output from the first temperature detecting unit exceeds a temperature threshold. The failure diagnosing unit blocks supply of the driving current to the load and outputs a signal of a level corresponding to a temperature out of a temperature range detectable by the second temperature detecting unit to the controller when it is determined that the first temperature detecting unit breaks down.