Pololu High-Power Stepper Motor Driver 36v8

Yes. To avoid damaging your stepper motor, you want to avoid exceeding the rated current, which is 600 mA in this instance. All of our stepper motor drivers let you limit the maximum current, so as long as you set the limit below the rated current, you will be within spec for your motor, even if the voltage exceeds the rated voltage. The voltage rating is just the voltage at which each coil draws the rated current, so the coils of your stepper motor will draw 600 mA at 3.9 V. By using a higher voltage along with active current limiting, the current is able to ramp up faster, which lets you achieve higher step rates than you could using the rated voltage.

If you do want to use a lower motor supply voltage for other reasons, consider using our DRV8834 or STSPIN-220 low-voltage stepper motor drivers.

Yes, you do! Setting the current limit on your stepper motor driver carrier is essential to making sure that it runs properly. An appropriate current limit also ensures that your motor is not allowed to draw more current than it or your driver can handle, since that is likely to damage one or both of them.

Setting the current limit on the Pololu High-Power Stepper Motor Driver is done through its SPI interface (this is very different from most of our other stepper motor driver carriers, which have their current limits set through their on-board potentiometers). The Pololu High-Power Stepper Motor Driver defaults to its maximum possible current limit setting on start-up, which is much more current than the board can safely deliver, so you will need to set the current limit to an appropriate value for your stepper motor before enabling the driver outputs to prevent damage to the board. This is done by adjusting the TORQUE and ISGAIN bits in the TORQUE and CTRL registers, respectively. The DRV8711 datasheet (1k redirect) has more information on how to set the current limit through the SPI interface, and our Arduino library for the Pololu High-Power Stepper Motor Driver includes example sketches showing how to implement this in software.