Patent application number | Description | Published |
20130069580 | PWM SIGNAL OUTPUT CIRCUIT - A PWM-signal-output circuit includes a detecting unit to detect periods in which a speed signal with logic level changing alternately and having a period corresponding to a motor-rotation speed is at one and the other logic levels, a dividing unit to divide each of the periods into first to third periods; a first output unit to change a PWM-signal duty-cycle in a stepwise manner toward an input-signal duty-cycle in the first period, a second output unit to cause a PWM-signal duty-cycle to become equal to an input-signal duty-cycle, to maintain a current flowing through the motor coil constant, in the second period; and a third output unit to change a PWM-signal duty-cycle in a stepwise manner from an input-signal duty-cycle, to decrease a current flowing through the motor coil, in the third period. | 03-21-2013 |
20130069702 | PWM SIGNAL OUTPUT CIRCUIT - A PWM-signal-output circuit includes a first output unit to output a PWM signal with a first duty cycle, in a first period in which a motor starts rotating, a second output unit to output the PWM signal whose duty cycle increases toward a second duty cycle and decreases from the second duty cycle in a period from a logic level change in speed signal until its subsequent logic level change, in a second period following the first, the speed signal having a period corresponding to a motor-rotation speed and a logic level changing alternately, and a third output unit to output the PWM signal whose duty cycle increases toward that of the input signal and thereafter decreases from that of the input signal in a period from a logic level change in the speed signal until its subsequent logic level change, after the second period elapses. | 03-21-2013 |
20130113401 | PWM SIGNAL OUTPUT CIRCUIT - A PWM-signal-output circuit includes a detecting unit to detect time periods during which a speed signal with logic level changing alternately and having a period corresponding to a motor-rotation speed is at one and the other logic levels; a generating unit configured to, when the logic level of the speed signal changes, generate a signal to increase and thereafter decrease a current flowing through a motor coil within a first time period detected by the detecting unit, in a second time period occurring after the first time period; and a second generating unit configured to, when the first time period has elapsed after a change in the logic level of the speed signal but before a subsequent change in the logic level thereof in the second time period, generate the signal from when the first time period has elapsed until when the logic level thereof changes. | 05-09-2013 |
20150180378 | MOTOR CONTROL CIRCUIT AND METHOD - 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. | 06-25-2015 |
20150180388 | MOTOR CONTROL CIRCUIT AND METHOD - In accordance with an embodiment, a method for driving a motor includes generating a position indicator signal in response to a signal from the at least one Hall sensor, wherein the position indicator signal has a first period. A phase shift value is generated using the position indicator signal. The position indicator signal is used to generate an adjusted position indicator signal in response to the phase shift value. In accordance with another embodiment, a lead angle adjustment circuit includes a counter coupled to a subtractor circuit through a multiplier circuit. A storage register is coupled to the output of the counter and to an input of a slope determination circuit, wherein the slope determination circuit is coupled to a first external pin of the lead angle adjustment circuit. A multiplier circuit is coupled to the slope determination circuit and to a second external pin. | 06-25-2015 |
20150180389 | MOTOR CONTROL CIRCUIT AND METHOD - In accordance with an embodiment, a method for driving a motor includes decreasing a duty of an input signal to a motor and decreasing a duty of a duty control signal in response to decreasing the duty of the input signal The duty of the duty control signal is maintained at a first level in response to a reverse current signal and decreased from the first level in the absence of the reverse current signal. In accordance with another embodiment a driver circuit includes a state controller having an input coupled to a pulse width modulation detection circuit and an output connected to a reverse current detection circuit. | 06-25-2015 |
20150180390 | MOTOR CONTROL CIRCUIT AND METHOD - In accordance with an embodiment, motor control circuit has a first selector connected to a second selector through an analog to digital converter. The first selector has an input that is connected to an external pin. In addition, the second selector has a plurality of inputs and a plurality of outputs, wherein a first register is connected to a first input and a second register is connected to a second output of the second selector. In accordance with another embodiment, at a beginning step of a method for setting a duty of a drive signal of a motor, a duty setting signal is applied to an external pin. The duty setting signal is converted into a digital duty setting signal. One of the digital duty setting signal or a predetermined duty signal is transmitted to a storage register. | 06-25-2015 |
20150180391 | MOTOR CONTROL CIRCUIT AND METHOD - In accordance with an embodiment, a drive circuit is provided for driving for a motor wherein the drive circuit includes a rotational state generation circuit connected to a state controller. The state controller is connected to a pulse width modulation detection circuit, a timer, and a duty control controller. In accordance with another embodiment, a method for driving the motor includes coupling a single Hall sensor to the motor and using the single Hall sensor to determine a position of a rotor of the motor. The drive circuit pulls the rotor so that one of its north pole or south pole is adjacent to the single Hall sensor. After the pole of the rotor is adjacent to the rotor, the motor starts. | 06-25-2015 |