Driver circuit and method

摘要

An amount of a motor drive current is controlled to an appropriate value. Two coils are provided, and a rotor is rotated by the coils by setting different phases for the supplied currents to the two coils. During a phase where one of the coils is in a high-impedance state, an induced voltage generated in the coil is detected. According to the state of the induced voltage, an output control circuit controls the amounts of the motor drive currents supplied to the two coils.

主权项

1. A driver circuit suitable for driving a motor, comprising:
an output control circuit having first and second inputs and an output; an output circuit having first and second inputs and a plurality of outputs configured for coupling to a plurality of coils of a 2-phase stepping motor; and a detecting circuit having a plurality of inputs and at least a first output, wherein first and second inputs of the plurality of inputs of the detecting circuit are coupled to first and second outputs of the plurality of outputs of the output circuit, respectively, the first output coupled to the second input of the output control circuit and the second output coupled to the second input of the output circuit, wherein the detecting circuit generates an adjustment signal at its first output in response to detecting an induced voltage at a first coil of the plurality of coils during a period when the first coil is in a high-impedance state and a second coil of the plurality of coils is driven with a first duty ratio.