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Bipolar Stepper Motor Driver with Stall Detection and Analog Supply =< 5V

Jeff Halio
Prodigy 80 points
Other Parts Discussed in Thread: DRV8711, DRV8835, DRV8834, DRV8833, DRV5023

My customer has only 5V and 3.3V rails on their board.  They are looking for a bipolar stepper motor that can operate with a minimum analog supply of =< 5V.  They also need to detect a stall.  I see that the DRV8711 supports stall detection, but it only goes down to 8V analog supply.  The motor drivers that support minimum analog supply of less that 5V do not support stall detection.  Are there any other options that we could recommend?

Output current at 1.5A RMS / 2A peak would be ideal.

  • 0
    TI__Guru** 114905 points

    Hi Jeff,

    Unfortunately, the DRV8711 is the only device that supports stall. As you mentioned, the voltage range is too high.

    Do you know what the stall is used for? Is it really a stall condition or an end of travel limit?

  • 0
    TI__Mastermind 20985 points

    Hi Jeff,

    You might want to consider running at a higher voltage than 5V, since that has advantages for steppers.  Have you verified you can meet your RPM target with just 5V?

    Low voltage controllers include the DRV8833, DRV8834, and DRV8835.  A separate rotary encoder can also be used to detect whether the motor is spinning.

    Best regards,
    RE

  • 0 in reply to Rick Duncan
    Prodigy 80 points

    Rick,

    Thank you for the quick reply!  Yes, it is an end-of-travel limit.  Typically, the customer's application where "know" where the end-of-travel limit should be.  If they experience a stall, then the application will assume that the motor is not in the position that it thought it was, and that will kick off a re-calibration process.

    Besides stall, is there another method that could be used in this scenario?

    Thank you, Jeff

  • 0 in reply to Jeff Halio
    TI__Guru** 114905 points

    Hi Jeff,

    We have seen micro switches or hall sensors used as end-of-travel limits. Either one works.

    The micro switch is self contained, where the hall requires a magnet in addition. The DRV5023 plus magnet is a good fit.

    FYI -- there is a hall sensor forum available for additional information.

  • 0 in reply to Rick Duncan
    Prodigy 80 points

    Thank you for the recommendations, but the customer would prefer not to use external sensors (and have to write MCU code to support the feedback).  They have found a stepper motor driver from another supplier that includes the stall detection feature and allows for 5V motor supply.  What are the benefits of using the DRV8711 with a higher power supply?  i.e. - higher RPM...what else?

    Thanks, Jeff

  • 0 in reply to Jeff Halio
    TI__Mastermind 20985 points

    Jeff, the DRV8711 has integrated 1/256 microstepping for ultra-smooth stepper motion.  This makes winding current vary like a sine wave, as shown in datasheet Figure 10.

    Current is further controlled by the adjustable "Decay".  That refers to current regulation at each microstep during the "off" period when current decreases.

    Also, PCB and device temperature will be low and efficient since the DRV8711 is a predriver for external FETs that have a lower Rds(on) than achievable with integrated FETs.

    There's also protection features as described on Page 23, and register options on the following pages that allow different dead time and sense amplifier gain.

    Best regards,
    RE