公开(公告)号：US20200266740A1

公开(公告)日：2020-08-20

申请号：US16869617

申请日：2020-05-08

Applicant: Texas Instruments Incorporated

Inventor： Sooping Saw ,  Rakesh Raja ,  Wen Pin Lin ,  Sudhir Nagaraj

IPC: H02P8/38 ,  H02P8/34 ,  H02P8/12

Abstract: In one embodiment, a method includes detecting, by a stall detection sensor in a driver coupled to a stepper motor, a first set of time-off periods in a rising commutation phase of motor current during current regulation. The stall detection sensor further detects a second set of time-off periods in a falling commutation phase of motor current during current regulation. Next, the stall detection sensor compares the first set of time-off periods with the second set of time-off periods and determines whether the stepper motor is stalled based on the comparison of the first set of time-off periods with the second set of time-off periods.

公开(公告)号：US10084402B2

公开(公告)日：2018-09-25

申请号：US15296031

申请日：2016-10-17

Applicant: Texas Instruments Incorporated

Inventor： Sooping Saw ,  Anuj Jain ,  Jeffrey Okyere ,  Wen Chao Qu

IPC: H02P8/32 ,  H02P8/34 ,  H02P8/12 ,  H02P6/08

CPC classification number: H02P8/32 ,  H02P6/085 ,  H02P8/12 ,  H02P8/22 ,  H02P8/34

Abstract: A stepper motor control system includes stepper motor error reduction. For example, first and second power switches respectively energize and de-energize a stepper motor coil during each cycle for pulse-width modulating (PWM) the coil current. During a cycle including a zero crossing microstep, a calibrator detects a type of a body diode effect that occurs in the second power switch when the second switch stops de-energization of the coil. A selected offset is adjusted in response to the type of detection of the body diode effect of the second power switch. Adjusting the selected offset controls the trigger time for a comparator for comparing an offset reference voltage to a motor voltage developed in response to the coil current. Progressively adjusting the selected offset over successive cycles compensates for delays of components in the PWM control loop and reduces errors resulting from, for example, process, voltage, and temperature variations.

公开(公告)号：US11418137B1

公开(公告)日：2022-08-16

申请号：US17235569

申请日：2021-04-20

Applicant: Texas Instruments Incorporated

Inventor： Sayantan Gupta ,  Sooping Saw

IPC: H02P6/28 ,  H02P7/29 ,  H02P21/22

Abstract: A motor driver includes a low-side drive transistor, a comparator, a sense transistor, first switch, and a second switch. The low-side drive transistor is adapted to be coupled to a motor. The comparator is configured to determine a direction of a drive current flowing in the low-side drive transistor. The sense transistor is coupled to the low-side side drive transistor and is configured to pass a replica of the drive current. The first switch is configured to couple the sense transistor to the low-side drive transistor responsive to the drive current flowing in a first direction through the low-side drive transistor. The second switch is configured to couple the sense transistor to a ground responsive to the drive current flowing in a second direction, that is opposite the first direction, through the low-side drive transistor.

公开(公告)号：US20200249648A1

公开(公告)日：2020-08-06

申请号：US16263766

申请日：2019-01-31

Applicant: TEXAS INSTRUMENTS INCORPORATED

Inventor： Rakesh Raja ,  Sudhir Nagaraj ,  Sooping Saw

IPC: G05B19/40 ,  H02M7/537 ,  G05D3/10 ,  H02K3/04

Abstract: A method for electrically producing a stalled state in a stepper motor having a first coil and a second coil is provided. The method includes driving a first sinusoidal current through the first coil, and driving a second sinusoidal current through the second coil, wherein the first and second sinusoidal currents are in phase.

公开(公告)号：US10063170B2

公开(公告)日：2018-08-28

申请号：US15619128

申请日：2017-06-09

Applicant: TEXAS INSTRUMENTS INCORPORATED

Inventor： Sooping Saw ,  Rakesh Raja ,  Anuj Jain ,  Matthew Hein

IPC: H02P8/14

CPC classification number: H02P8/14 ,  H02P6/182

Abstract: In a described example an apparatus includes: an FET driver circuit configured to supply current to a coil in a stepper motor, the FET driver circuit configured to regulate the current to the coil using a fixed delta current; a current chopper pulse width modulated circuit coupled to the FET driver circuit configured to supply pulses corresponding to a step control signal and a direction control signal; a back electromotive force (BEMF) monitor coupled to the current chopper circuit configured to measure an off time pulse and to output a BEMF monitor signal; and a controller coupled to the current chopper pulse width modulated circuit to supply the step and direction control signals and coupled to receive the BEMF monitor signal.

公开(公告)号：US20180109213A1

公开(公告)日：2018-04-19

申请号：US15296031

申请日：2016-10-17

Applicant: Texas Instruments Incorporated

Inventor： Sooping Saw ,  Anuj Jain ,  Jeffrey Okyere ,  Wen Chao Qu

IPC: H02P8/32 ,  H02P8/34 ,  H02P8/12 ,  H02P6/08

CPC classification number: H02P8/32 ,  H02P6/085 ,  H02P8/12 ,  H02P8/34

Abstract: A stepper motor control system includes stepper motor error reduction. For example, first and second power switches respectively energize and de-energize a stepper motor coil during each cycle for pulse-width modulating (PWM) the coil current. During a cycle including a zero crossing microstep, a calibrator detects a type of a body diode effect that occurs in the second power switch when the second switch stops de-energization of the coil. A selected offset is adjusted in response to the type of detection of the body diode effect of the second power switch. Adjusting the selected offset controls the trigger time for a comparator for comparing an offset reference voltage to a motor voltage developed in response to the coil current. Progressively adjusting the selected offset over successive cycles compensates for delays of components in the PWM control loop and reduces errors resulting from, for example, process, voltage, and temperature variations.