thanks for your reply,
we have 2.8v 1.7a nema 17 stepper motor and a4988
can we use a4988 for our motor?
our motor voltage is 2.8v but a4988 motor power supply is 8 to 35 so wihch can we using voltage or power supply
Our A4988 motor drivers can only provide about 1 A (for the regular version) or 1.2 A (for the black edition) per phase continuously, so they would not be able to provide the 1.7A/phase that stepper motor is designed to work at. The DRV8825 is probably a better choice for that motor, but still can only provide about 1.5A/phase continuously without supplementary cooling, so the output torque from the motor would be a little below its specification.
Since both the DRV8825 and A4988 are current limiting drivers, any supply voltage above the minimum and below the maximum supply voltage for the stepper driver should work with your 2.8 V rated motor. However, you must set the current limit for the driver to prevent it from supplying more current than your motor is rated for. You can see more about that in the first FAQ on any of our stepper motor driver carrier product pages.
The Black edition says it can handle up to 2A, could that work?
The A4988 driver chip itself can handle up to 2A with sufficient additional cooling, but without taking additional cooling measures, the black edition or our carrier can only deliver about 1.2A in an open, room temperature environment.
If I do set the current limit to 1.2 A I will not be able to achieve the full output torque stated in the datasheet?
Correct, you will not be able to achieve the full rated output torque listed in the motor datasheet if the motor’s rated current is higher than your configured current limit. If you want to maximize the torque from your motor, then you might consider using a stepper motor driver that can handle more current. Another option with any driver is to try adding additional cooling (such as with a heat sink or forced airflow) to increase how much current it can handle.