Drive circuit for driving a capacitive load

A drive circuit for driving a capacitive load, comprising:

• a modulation circuit that generates a modulated signal by pulse-modulating a source signal;
• a transistor that amplifies the modulated signal to generate an amplified modulated signal;
• a low-pass filter that includes an inductor and a capacitor and smoothes the amplified modulated signal to generate a drive signal which is applied to the capacitive load;
• a feedback circuit that returns the drive signal to the modulation circuit;
• and
• a circuit board on which the modulation circuit, the transistor, the low-pass filter, and the feedback circuit are mounted,
• wherein the circuit board has a first mounting surface and a second mounting surface,
• wherein the capacitor and the feedback circuit are mounted and a first ground wiring connected to the capacitor and a second ground wiring connected to the feedback circuit are provided on the first mounting surface, and
• wherein at least one of the modulation circuit, the transistor, and the inductor is mounted on the second mounting surface.