A driving device includes a voltage regulator, a voltage generator, and a first NMOSFET. The voltage regulator is coupled between a first high-voltage terminal and the output terminal of the driving device. The voltage regulator receives the first high voltage of the first high-voltage terminal. The voltage regulator steps down the first high voltage to generate a supply voltage. The voltage generator is coupled to a second high-voltage terminal and the output terminal of the driving device. The voltage generator provides a reference voltage for the output terminal of the driving device. The reference voltage is substantially lower than the supply voltage. The first NMOSFET is coupled between the output terminal of the driving device and a low-voltage terminal.