Confusion on stepper motor drivers

I am slightly confused about what the current ratings for stepper motor drivers are referring to. The DRV8825 high current stepper motor driver is the one i plan on using,

https://www.pololu.com/product/2133

IT specifies that it is rated for 1.5a per phase 2.2a per phase with additional cooling elements, so does that mean in a 2 phase stepper motor is rated for 3a or up to 4.4a, with additional heatsink, per motor???

The reason i ask is i am trying to run this stepper motor, https://www.pololu.com/product/1478 but i want to make sure i dont burn up the motor. I am just confused on what exactly the specifications on the stepper motor driver are telling me and what i need to be looking for when buying a motor driver to contol the motor i need. i am brand new to arduino so any input is helpful thanks.

That motor requires a driver comfortably capable of producing 2.8amps so the DRV8825 is not suitable. Look for a driver that can provide 3 amps per phase or more. Unfortunately they will be more expensive.

The Thread stepper motor basics may be useful.

...R

Steppers are rated by current amplitude per phase, as are drivers, you can't throw in an optimistic factor of 2!

Incidentally driver losses/heating go up as current squared so a factor of 2 is really a factor of 4 in heat...