We have been using the DRV8824 in a design for a while now, and just got back a field failure where the driver was not stepping about 10% of the time that the STEP control signal was active. Further investigation showed that this step skipping probability increased if the duration of the STEP control signal was less than 2.3uS, but still being greater than the minimum duration that we provide, which is 2.2uS. The spec calls out a minimum required duration of 1.9uS, so we should be OK on all fronts. But with this in mind, we took a look at some other boards with the DRV8824, and it turns out that those as well are skipping steps, although it is at a rate of less than 1%.
When we change the STEP duration to greater than 4uS, we do not skip any pulses on any of the units that we have on hand.
I have attached the spec that I have which shows the 1.9uS requirement.
Is there some condition that can influence this requirement? Or might it just be wrong in the spec?
Thanks in advance,
