A waveform conversion circuit for converting a control signal of a control node ranging from a high voltage level to a low voltage level of a reference node into a driving signal of a first node is provided. The waveform conversion circuit includes a first resistor, a unidirectional conducting device, and a voltage clamp unit. The first resistor is coupled between the control node and the first node. The unidirectional conducting device unidirectionally discharges the first node to the control node. The voltage clamp unit is coupled between the first node and the reference node and is configured to clamp a driving signal.