Hi all,
Can the expert help to advise on this application:
1. The current limit for the DRV8825 copper drive is governed by the equation Ichop = Vref/(5xRsense). Please confirm if the current is referring to the peak current.
2. Our desired current from motor driver is 340mArms through to the motor winding. Under the assumption that Ichop is referring to peak current, the equivalent peak current limit should be 480mArms. The application do not achieve 340mArms and it is less than this by 60mArms.
3. We achieve 340mArms through the winding only when the following setting is followed:
Vref = 1.4125V
Rsense=0.5 ohm
Again, theoretically this corresponds to Ichop (peak) = 565mA which corresponds to 400mArms. Again, there is a delta of 60mArms between set value and measured value.
4. For our application, which requires only 340mArms nominally, is it acceptable to use DRV8825 with a current driving capability of 2.5A? If not, do you have any alternate suggestion without software impact?