I have a pololu DRV8825, and I would like to use it in a project to control a stepper motor that has a very low current,
0.120 A, so right now I use VREF = 0.060 V.
This VREF value is very low and according to datasheet the performance is degraded for low VREF, so I would like to replace the Rsense (0.1 ohm @ 0.5 watt) for a higher one that lets me use a better VREF.
Even the pololu DRV8824 uses a Rsense (0.33 ohm @ 0.5 watt) too low for the application I want.
If I change Rsense to 2 ohm @ 0.25 watt, I would be able to set VREF to 1.2 V and get the best performance from the driver.
Unfortunatelly I see too many different resistors out there to buy and I’m looking for some guidance, so my question is what size and special characteristics shall the 2 ohm resistor have (%precision, resistor case style, mounting, lenght/depth, etc) to make the replacement without mistakes? Thank you in advance.