The device has a plasma-generating plug with a capacitive inductive resonator (RS2), an oscillator (OSC) generating a high-frequency control pulse sequence, and a periodic pulse voltage generator (GENI) with a switching power transistor (M1). The transistor has a control electrode connected to the oscillator output and to a drain (D) delivering a voltage pulse sequence to the resonator in response to control pulses received on the electrode. A zener diode (D1) is connected between the drain and a source of the transistor and limits the voltage difference between the drain and source.
