A phase-locked loop includes: a variable oscillator connected to a first resonator, said oscillator being able to deliver an output signal at a first output frequency Fout1, a first frequency divider receiving the output signal and able to convert it into a divided frequency signal Fout1/n, a reference oscillator connected to a second so-called reference resonator, delivering a reference signal at a low reference frequency Fref, generating an electrical dissipation lower than a microampere, a phase comparator measuring the phase error between the divided frequency signal Fout1/n and the reference signal and being able to produce a test signal, a low-pass filter or an integrating circuit able to filter the test signal and able to generate a voltage or a control word designed to control the voltage-controlled or digitally controlled oscillator.