I purchased this driver a few weeks back. While adjusting the current limit potentiometer, the device failed. My VMOT supply is 40 volts and I was trying to adjust to an Vref of 1.0 volt. I am wondering what may have happened to cause this failure. Any ideas. I don’t want to order another device unless i figure out why this may have occurred. Thank you
Jack
Hello, Jack.
I am sorry you are having trouble with your DRV8825. How did it fail? (Did any of the components blow up?)
40 V is very close to the maximum voltage rating of the DRV8825 (45 V), which does not leave a lot of room for inductive voltage spikes and other voltage irregularities. This is especially an issue if your power leads are more than a few inches long. On the driver’s product page, we have a note discussing this and recommending the use of a large capacitor; are you using such a capacitor in your setup? Could you post a clear picture showing how you had the driver connected?
- Kevin
Kevin,
I no longer have it connected – Replaced with a4988 I had; but changed to 12 volt Vmot. The A4988 is working OK, but I have had to reduce the current limit below what I would like to have. I moved the two electrolytics you see in the photo from the DRV8825 to the A4988. I don’t know if the second phot is clear enough, but there is a small burnt spot around pin 4. I do have about 30 inch power supply leads, but thought the electrolytics would allow that. Thanks,
Jack
http://s1340.beta.photobucket.com/user/Jack_Generaux/media/photo-1.jpg.html
http://s1340.beta.photobucket.com/user/Jack_Generaux/media/photo.jpg.html?sort=3&o=0
That looks pretty consistent with damage caused by a voltage spike. What are the values of the capacitors? I would suggest either adding more capacitance or using a lower voltage to hopefully prevent this from happening again. (By the way, you shouldn’t really need a big capacitor between VDD and ground; that capacitor would probably be more useful in parallel with the other one, across VMOT and ground.)
If you would like to try again with another driver, please email us directly with your order information and we can probably offer you a discount on a replacement.
- Kevin
