Driving circuit for voice coil motor having a first driver coupled to a first end of a coil and a second driver coupled to a second end of the coil

摘要

With a driving current as I_DRV, with a reference voltage as V_REF, and with a gain as k, a current detection circuit generates a detection voltage V_S represented by V_S=V_REF+k×I_DRV. An error amplifier amplifies a difference between the detection voltage V_S and a control voltage that indicates a position of the VCM so as to generate an error voltage V_ERR. A first driver switches the driving current I_DRV between a source current and a sink current with respect to one end of the coil according to the error voltage V_ERR. A second driver switches the driving current I_DRV between a sink current and a source current with respect to the other end of the coil according to the error voltage V_ERR. The driving circuit allows an external circuit to set the level of the reference voltage V_REF.