Patent ID: 8860338
Filing Date: 2014-10-14
Classification: H02P

Abstract:
1. A motor drive circuit comprising: a digital filter configured to attenuate amplitude in a frequency band including a resonance frequency of an actuator in a target current signal, the target current signal being a digital signal indicative of a target value of a drive current, the drive current being supplied to a voice coil motor configured to drive the actuator; a digital-analog converter configured to convert an output signal of the digital filter into an analog signal, and output the converted analog signal as a current control signal; a drive circuit configured to supply the drive current to the voice coil motor according to the current control signal; and a selecting circuit configured to select either a first mode, in which a step signal is inputted as the target current signal and the step signal is supplied to the digital-analog converter, or a second mode, in which the inputted target current signal is supplied to the digital filter, according to a mode selection signal, wherein in the first mode, the digital-analog converter converts the step signal into the analog signal, and outputs the converted analog signal as the current control signal, and wherein in the second mode, the digital filter has the frequency band to be attenuated in amplitude set therefor according to the resonance frequency measured in advance in the first mode.