Motor control circuit and method
AssigneeSemiconductor Components Industries, LLC
InventorTakashi Ogawa
Life of this patent
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Abstract
In accordance with an embodiment, a stopping circuit includes a detection circuit connected to a subtraction amount determination circuit. A subtraction circuit is connected to the subtraction circuit and the subtraction circuit is coupled for receiving an output signal from the subtraction amount determination circuit. A duty determination is connected to the subtraction circuit and a state controller is connected to the duty determination circuit. A counter is connected to a state controller. In accordance with another embodiment a method for stopping a motor is provided by decreasing a duty of a drive signal. The duty of the drive signal is lowered from a first level to a predetermined level. A braking state is entered in response to the duty of the pulse width modulation signal achieving the predetermined level.
Claims19
A method for stopping a motor, comprising:
- in response to an input pulse width modulation signal being off, generating a pulse width modulation off signal;
- decreasing a duty of a drive signal to a driver circuit;
- in response to the pulse width modulation off signal;
- comparing the duty of the drive signal with a predetermined level;
- in response to the duty of the drive signal being greater than the predetermined level, continue decreasing the duty of the drive signal;
- in response to the duty of the drive signal being less than or equal to the predetermined level, entering a braking state which includes turning off a first transistor;
- and
- in response to the motor stopping, performing high impedance processing including turning off a second transistor.
A method for stopping a motor, comprising:
- providing a drive circuit configured to drive the motor;
- providing a drive signal that has a duty at a first level, wherein the drive signal is configured to drive the motor;
- reducing the duty of the drive signal from the first level in response to a pulse width modulation (PWM) OFF signal that indicates that an input PWM signal is off;
- and
- entering a braking state in response to the duty of the drive signal achieving a predetermined level which includes turning off a first transistor;
- in response to the motor stopping, performing high impedance processing including turning off a second transistor.
Dependencies are inferred from the claim text.