Part Number:DRV8823
Hello,
I am trying to size the resistor (ohms and wattage) for the current limiting sense pins (AISEN, BISEN, CISEN, and DISEN) so the full 1.5A of current drive is enabled. The DRV8823EVM (evaluation board) uses a 0.33 ohm 2W resistor. I understand how the 0.33 ohms was determined, but I don't see anywhere stating what the wattage needs to be or how to calculate it. The motors I will be using will be running on 12VDC.
Unknown, but is the DRV8823EVM capable of the full 1.5A? Was the 2W resistor calculated assuming 32VDC input with 1.5A, so if there is a I(chop) factor of 5 and a factor of 8 (ABVREF and CDVREF compared to the VM) then the calculation would be ((32V*1.5A)/5)/8 = 1.2W, so a 2W resistor was used? Unknown if this is how to calculate the resistor wattage.