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 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 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 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.

Abstract: An integrated circuit includes an H-bridge circuit having a first output node for coupling to a high-side terminal of an inductor and a second output node for coupling to a low-side terminal of the inductor. A current source is coupled in series with a current sense FET between a digital upper supply voltage and the first output node, wherein during a fast decay mode, a gate of the current sense FET is coupled to be turned on. A current-sense comparator includes a first input coupled to a sensing node between the current source and the current sense FET, a second input coupled to the lower supply voltage and an output coupled to a driver control circuit.

Abstract: A circuit includes an input terminal, a first transistor, a second transistor, a comparator, a voltage reference circuit, and a control circuit. The first transistor includes a first terminal coupled to the input terminal. The second transistor includes a first terminal coupled to the input terminal. The comparator includes a first terminal coupled to the input terminal. The voltage reference circuit is coupled to a second terminal of the comparator. The control circuit includes an input, a first output, and a second output. The input is coupled to an output of the comparator. The first output is coupled to a second terminal of the first transistor. The second output is coupled to a second terminal of the second transistor.

Abstract: An integrated circuit includes an H-bridge circuit having a first output node for coupling to a high-side terminal of an inductor and a second output node for coupling to a low-side terminal of the inductor. A current sense FET is coupled between a current source and the lower supply voltage to provide a reference current that includes a peak current limit at a sensing node. A current-sense comparator has a first input coupled to the sensing node, a second input coupled to the second output node and an output coupled to send an output signal towards a driver control circuit. A FET linear detection circuit is coupled to receive a gate voltage of an active low-side power FET and has an output coupled to enable the current-sense comparator when the active low-side power FET is operating in a linear region.

Abstract: A circuit includes an input terminal, a first transistor, a second transistor, a comparator, a voltage reference circuit, and a control circuit. The first transistor includes a first terminal coupled to the input terminal. The second transistor includes a first terminal coupled to the input terminal. The comparator includes a first terminal coupled to the input terminal. The voltage reference circuit is coupled to a second terminal of the comparator. The control circuit includes an input, a first output, and a second output. The input is coupled to an output of the comparator. The first output is coupled to a second terminal of the first transistor. The second output is coupled to a second terminal of the second transistor.

Abstract: An integrated circuit includes an H-bridge circuit having a first output node for coupling to a high-side terminal of an inductor and a second output node for coupling to a low-side terminal of the inductor. A current sense FET is coupled between a current source and the lower supply voltage to provide a reference current that includes a peak current limit at a sensing node. A current-sense comparator has a first input coupled to the sensing node, a second input coupled to the second output node and an output coupled to send an output signal towards a driver control circuit. A FET linear detection circuit is coupled to receive a gate voltage of an active low-side power FET and has an output coupled to enable the current-sense comparator when the active low-side power FET is operating in a linear region.

Abstract: An integrated circuit includes an H-bridge circuit having a first output node for coupling to a high-side terminal of an inductor and a second output node for coupling to a low-side terminal of the inductor. A current source is coupled in series with a current sense FET between a digital upper supply voltage and the first output node, wherein during a fast decay mode, a gate of the current sense FET is coupled to be turned on. A current-sense comparator includes a first input coupled to a sensing node between the current source and the current sense FET, a second input coupled to the lower supply voltage and an output coupled to a driver control circuit.

Abstract: A stepper driver for a motor includes an H-bridge, a sense transistor coupled to the H-bridge, a voltage-to-current (Vtol) converter, and a sine digital-to-analog converter (DAC). The Vtol converter has a Vtol converter input and a Vtol converter output. The Vtol converter output is coupled to the sense transistor. The sine DAC has a sine DAC digital input, a reference input, and a sine DAC output. The sine DAC output is coupled to the Vtol converter input. The sine DAC includes an R-2R network, an offset control circuit coupled to the R-2R network, and a gain control circuit also coupled to the R-2R network.

Abstract: A stepper driver for a motor includes an H-bridge, a sense transistor coupled to the H-bridge, a voltage-to-current (VtoI) converter, and a sine digital-to-analog converter (DAC). The VtoI converter has a VtoI converter input and a VtoI converter output. The VtoI converter output is coupled to the sense transistor. The sine DAC has a sine DAC digital input, a reference input, and a sine DAC output. The sine DAC output is coupled to the VtoI converter input. The sine DAC includes an R-2R network, an offset control circuit coupled to the R-2R network, and a gain control circuit also coupled to the R-2R network.

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.