A sine wave generator includes a resonator circuit, a control circuit and a pulse generator. The resonator circuit is configured to receive energy pulses and to generate a resonator sinusoidal signal responsively to the energy pulses. The control circuit is configured to estimate a signal measure of the resonator sinusoidal signal, or of a signal derived from the resonator sinusoidal signal. The pulse generator is configured to generate the energy pulses responsive to the signal measure estimated by the control circuit, and to drive the resonator circuit with the energy pulses.