Analysis and Modeling Voice-Coil Motor Displacement Change Using an Electrical Simulation Method

Voice coil motor (VCM) is a special type of direct current drive motor, which generates the force in the magnetic field by using the current coil. And the force is proportional to the current through the coil. In the smart phone camera module, the automatic focusing function of the mobile phone lens is realized by controlling the current of the voice coil motor. This paper presents a method of using the second-order effect of RLC circuit to achieve the unification of electrical and mechanical balance by means of voltage-controlled current source. The change of displacement of voice coil motor is equivalent to the change of capacitor voltage of RLC circuit, so that the change of displacement of VCM can be represented by the change of voltage of electrical components. The establishment of the equivalent model can realize the unification of VCM's displacement change with other electrical characteristics by circuit design, which is of great help to the study of displacement change and other performance of the system.