L6470 step loss A (or B)

[spelger]

Posted on July 21, 2014 at 23:12

i've been using the L6470 driver successfully but have noticed that i get step loss on the a and b bridge. the data sheet indicates that when this happens the appropriate bits in the status register get set. unfortunately, the data sheet does not indicate how this is being determined (if it has i missed it and so has a search through the .pdf file).

sometimes these bits are cleared with or without an over current condition/under voltage condition. i am interested in knowing the reason for the step loss so i can take action to prevent this. if anyone can point me in the right direction i'd be thankful. scott #l6470 #step-loss

[spelger]

Posted on August 12, 2014 at 15:26

for what it is worth to anyone looking i found that by increasing the stall threshold current (STALL_TH) i could eliminate the step loss. the amount of current (as measured on a scope) did not exceed the programmed threshold but regardless i needed to increase it. i do not recall what i measured or what i had originally set it to but it was surely less than an amp (by measurement). i increased the threshold to 2.5 amps to take care of this.