Chandrasekhar Venkat
Department of Physics, Northwestern University, Evanston, Illinois 60208, USA.
Rev Sci Instrum. 2020 Feb 1;91(2):023705. doi: 10.1063/1.5131657.
An inexpensive yet versatile transducer controller for non-contact scanning probe microscopy (SPM) based on a PIC32 microcontroller from Microchip Technology, Inc is described. In addition to feedback control using the amplitude or phase of the signal from the non-contact transducer, the controller includes a phase-locked loop for frequency-shift feedback, as well as fixed-amplitude, quality factor (Q) control, and self-excitation modes. Apart from the input amplifiers, output buffers, and the Q-control circuit, all other functions of the controller are instantiated in software on the microchip, enabling rapid changes in operating parameters if needed. The controller communicates with a host personal computer via a simple serial connection. The controller has been tested with a quartz tuning-fork transducer but can be used with any oscillating non-contact transducer.
介绍了一种基于Microchip Technology, Inc的PIC32微控制器的低成本通用非接触扫描探针显微镜（SPM）换能器控制器。除了使用来自非接触换能器的信号幅度或相位进行反馈控制外，该控制器还包括用于频移反馈的锁相环，以及固定幅度、品质因数（Q）控制和自激模式。除了输入放大器、输出缓冲器和Q控制电路外，控制器的所有其他功能都在微芯片上通过软件实现，如有需要可快速改变操作参数。该控制器通过简单的串行连接与主机个人计算机通信。该控制器已使用石英音叉换能器进行了测试，但可与任何振荡非接触换能器配合使用。
