Abstract: A circuit includes an amplifier having a first input, a reference input, and an output. A pulse width modulator (PWM) controller has an input coupled to the output of the amplifier. A first switch has a control terminal coupled to an output of the PWM controller. A second switch has a second terminal coupled to the second terminal of the first switch, and has a control terminal coupled to the output of the PWM controller. An input of a current sensor is coupled to the second terminal of the first switch and is coupled to a second terminal of the second switch. An output of the current sensor is coupled to the first input of the amplifier. A duty cycle monitoring and reference signal adjustment circuit has an input coupled to the output of the PWM controller and has an output coupled to the reference input of the amplifier.

Abstract: An example apparatus includes: memory including machine-readable instructions; programmable circuitry configured to execute the machine-readable instructions of the memory configured to: determine a first value of power transferred to a stepper motor during a first operation of the stepper motor; determine a second value of power transferred to the stepper motor during a second operation of the stepper motor; determine a load angle of power delivered by the stepper motor during the first operation and second operation of the stepper motor based on the first value, the second value, and a stall power; and compare the load angle to a stall threshold to detect a stall of the stepper motor.

Abstract: In some examples, an apparatus includes a filter having first and second inputs, a current signal input, and an output. The apparatus also includes a speed observer having a voltage signal input, a current signal input, and an output, the output of the speed observer coupled to the second input of the filter. The apparatus also includes a ripple counter having an input and an output, the input of the ripple counter coupled to the output of the filter. The apparatus also includes a ripple processor having first and second inputs, and an output, the first input of the ripple processor coupled to the output of the ripple counter, the second input of the ripple processor coupled to the output of the speed observer, and the output of the ripple processor coupled to the first input of the filter.

Abstract: A stepper motor controller includes a first error amplifier, a second error amplifier, and a comparator. The first error amplifier has a first input adapted to be coupled to a current sensor to receive a sensed drive current, a second input adapted to receive an expected drive current and an output to provide a first error signal based on a comparison of the sensed drive current and the expected drive current. The second error amplifier has a first input adapted to be coupled to a voltage sensor to receive a sensed drive voltage, a second input coupled to the output of the first error amplifier and an output to provide a second error signal based on a comparison of the sensed drive voltage and the first error signal. The comparator has a first input adapted to receive a reference signal, a second input coupled to the output of the second error amplifier and an output to provide a stepper motor control signal based on a comparison of the reference signal and the error signal.

Abstract: In described examples, an integrated circuit includes first and second transistors, a switch, a capacitor, a resistor, and first and second comparators. A first terminal of the switch is coupled to a first terminal of the resistor. A second terminal of the switch is coupled to a second terminal of the resistor, a first terminal of the capacitor, and a gate of the first transistor. The first comparator is configured to receive at the first input a first reference voltage, and an output of the first comparator is coupled to a gate of the second transistor. The second comparator is configured to receive at the first input a second reference voltage. A second input of the second comparator is coupled to a second input of the first comparator. An output of the second comparator is coupled to a control input of the switch.

Abstract: In described examples, a method of testing an integrated circuit design under verification (DUV) includes selecting first and second stimulus-response data to generate a model, and adjusting model training data in response to model accuracy. The first stimulus-response data is selected from stimulus-response data for a known-good design similar to the DUV. The second stimulus-response data is selected from stimulus-response data for the DUV. The model is trained using the first and second stimulus-response data. A first correlation measure verifies model accuracy with respect to trained DUV stimulus-response data. A second correlation measure verifies model accuracy with respect to untrained DUV stimulus-response data.

Abstract: A motor controller including load angle error determination circuitry for determining a load angle error based on a difference between a motor load angle and a reference load angle. The motor load angle indicates an angle between a stator magnetic field and a rotor magnetic field of a motor. The motor controller includes current control circuitry for setting a current level for the motor based on the load angle error. The motor controller includes reference load angle control circuitry for setting the reference load angle based on the current level.

Abstract: A motor control system and method for controlling a brushed direct current (BDC) motor using a feedback loop based on a corrected ripple count. Motor control circuitry, for example implemented in digital logic such as a microcontroller, receives a coil current signal and a motor voltage signal. Discontinuities in the coil current signal, such as caused by commutation of the BDC motor, are counted to generate a ripple count. An observer function derives an angular frequency model estimate for the values of the coil current and motor voltage signals using a computational model for the motor. A corrected ripple count is generated based on a comparison of a commutation angle of the motor with an angular position based on the angular frequency model estimate over a time interval between discontinuity pulses. A motor drive signal is adjusted based on the corrected ripple count.

Abstract: Motor driver circuitry including driver transistors coupled to first and second output terminals, gate driver circuitry with outputs coupled to gate terminals of the driver transistors, controller circuitry coupled to the gate driver circuitry, a trip limit current source, an open-load limit current source, comparator circuitry, and fault detect circuitry. The comparator circuitry is coupled to the driver transistors, to the trip limit current source, and to the open-load limit current source. The comparator circuitry compares a drive current at the driver transistors with a trip limit current responsive to a signal from the controller indicating a standstill state, and configured to compare the driver current with an open-load limit current responsive to the signal indicating a motor running state. The fault detect circuitry has an input coupled to the comparator output and has a fault output.

Abstract: A method for controlling a stepper motor includes calculating a duty cycle of a current provided to the stepper motor and comparing a difference, between the calculated duty cycle and a base duty cycle of current provided to the stepper motor under a base load condition, to a reference duty cycle value. The method also includes adjusting a peak current level of the current provided to the stepper motor responsive to the comparison.

Abstract: A motor control system and method for a brushed direct current (BDC) motor using a compensated and corrected ripple count. Motor control circuitry, for example implemented in digital logic such as a microcontroller, receives a coil current signal and a motor voltage signal. Discontinuities in the coil current signal, are counted to generate a ripple count. An observer function derives an angular frequency model estimate using a computational model for the motor applying motor parameters estimated in an initial estimation interval following startup of the motor. A corrected ripple count is generated based on a comparison of a commutation angle of the motor with an angular position based on the angular frequency model estimate. Compensation for cumulative error over the initial estimation interval is derived from a behavioral motor model applying the estimated motor parameters. A motor drive signal is adjusted based on the compensated corrected ripple count.

Abstract: In accordance with at least one example of the description, a circuit is adapted to be coupled to a coil of a motor via an H-bridge circuit. The circuit includes a duty sensor, a subtractor, and a comparator. The duty sensor is coupled to the coil of the motor and is configured to provide raw run duty data responsive to a coil current through the coil. The subtractor is coupled to the duty sensor and is configured to provide a differential duty signal responsive to a stall duty signal and a run duty signal obtained using the raw run duty data. The comparator is coupled to the subtractor and is configured to provide a stall signal indicative of a stall condition for the motor responsive to the differential duty signal and a threshold value.

Abstract: In accordance with at least one example of the description, a circuit is adapted to be coupled to a coil of a motor via an H-bridge circuit. The circuit includes a duty sensor, a subtractor, and a comparator. The duty sensor is coupled to the coil of the motor and is configured to provide raw run duty data responsive to a coil current through the coil. The subtractor is coupled to the duty sensor and is configured to provide a differential duty signal responsive to a stall duty signal and a run duty signal obtained using the raw run duty data. The comparator is coupled to the subtractor and is configured to provide a stall signal indicative of a stall condition for the motor responsive to the differential duty signal and a threshold value.

Abstract: A motor control system and method for controlling a brushed direct current (BDC) motor using a feedback loop based on a corrected ripple count. Motor control circuitry, for example implemented in digital logic such as a microcontroller, receives a coil current signal and a motor voltage signal. Discontinuities in the coil current signal, such as caused by commutation of the BDC motor, are counted to generate a ripple count. An observer function derives an angular frequency model estimate for the values of the coil current and motor voltage signals using a computational model for the motor. A corrected ripple count is generated based on a comparison of a commutation angle of the motor with an angular position based on the angular frequency model estimate over a time interval between discontinuity pulses. A motor drive signal is adjusted based on the corrected ripple count.

Abstract: A motor control system and method for a brushed direct current (BDC) motor using a compensated and corrected ripple count. Motor control circuitry, for example implemented in digital logic such as a microcontroller, receives a coil current signal and a motor voltage signal. Discontinuities in the coil current signal, are counted to generate a ripple count. An observer function derives an angular frequency model estimate using a computational model for the motor applying motor parameters estimated in an initial estimation interval following startup of the motor. A corrected ripple count is generated based on a comparison of a commutation angle of the motor with an angular position based on the angular frequency model estimate. Compensation for cumulative error over the initial estimation interval is derived from a behavioral motor model applying the estimated motor parameters. A motor drive signal is adjusted based on the compensated corrected ripple count.

Abstract: A stepper motor driver includes an H-bridge including first and second outputs. The H-bridge includes a low-side transistor coupled between the first output and a ground. A reference current circuit is configured to produce a reference current. The reference current circuit has a reference output. An averager circuit includes an input and output. The input of the averager circuit is coupled to the first output of the H-bridge. A comparator includes first and second comparator inputs. The first input of the comparator is coupled to the output of the average circuit and the second input of the comparator is coupled to the reference output.

Abstract: A method for controlling a stepper motor includes calculating a duty cycle of a current provided to the stepper motor and comparing a difference, between the calculated duty cycle and a base duty cycle of current provided to the stepper motor under a base load condition, to a reference duty cycle value. The method also includes adjusting a peak current level of the current provided to the stepper motor responsive to the comparison.

Abstract: A stepper motor controller includes a first error amplifier, a second error amplifier, and a comparator. The first error amplifier has a first input adapted to be coupled to a current sensor to receive a sensed drive current, a second input adapted to receive an expected drive current and an output to provide a first error signal based on a comparison of the sensed drive current and the expected drive current. The second error amplifier has a first input adapted to be coupled to a voltage sensor to receive a sensed drive voltage, a second input coupled to the output of the first error amplifier and an output to provide a second error signal based on a comparison of the sensed drive voltage and the first error signal. The comparator has a first input adapted to receive a reference signal, a second input coupled to the output of the second error amplifier and an output to provide a stepper motor control signal based on a comparison of the reference signal and the error signal.

Abstract: A driver circuit includes a first switch which has a first terminal coupled to a voltage supply terminal, a second terminal coupled to a high-side gate, and a third terminal coupled to receive a voltage supply enable signal. The first switch is operable to connect the voltage supply terminal to the high-side gate responsive to the voltage supply enable signal. The driver circuit includes a second switch which has a first terminal coupled to a charge pump terminal, a second terminal coupled to the high side gate, and a third terminal coupled to receive a charge pump enable signal. The second switch is operable to connect the charge pump terminal to the high-side gate responsive to the charge pump enable signal.

Abstract: A driver circuit includes a first switch which has a first terminal coupled to a voltage supply terminal, a second terminal coupled to a high-side gate, and a third terminal coupled to receive a voltage supply enable signal. The first switch is operable to connect the voltage supply terminal to the high-side gate responsive to the voltage supply enable signal. The driver circuit includes a second switch which has a first terminal coupled to a charge pump terminal, a second terminal coupled to the high side gate, and a third terminal coupled to receive a charge pump enable signal. The second switch is operable to connect the charge pump terminal to the high-side gate responsive to the charge pump enable signal.