Abstract:Quartz tuning fork has the advantages of stable harmonic frequency and high quality factor, which is suitable for making atomic force microscope probe. In this paper, the driving circuit of quartz tuning fork probe, which includes preamplifier, self-excited oscillation and phase-locked loop (PLL) circuit system, is analyzed. The parameters of electronic devices that affect the performance of the circuit system are analyzed. In the drive circuit, the resonant frequency of quartz tuning fork can be detected and automatically compensated, and the PLL circuit is simulated and verified. The test results show that the circuit system meets the requirements of atomic force microscope.