Hi expert
I can't found rise & fall time in the datasheet.
my customer require step motor driver device rise time <200ns and fall time <180ns
can we device specify it?
Meng,
That is called slew rate in our datasheet and the DRV8889-Q1 is MUCH slower than that. Because of EMC concerns, automotive customers prefer slower edges to avoid radiated emission issues.
Is there something different about your customer's application that is driving these very fast rise/fall time specifications?
Regards,
Ryan
Meng,
Your calculation is correct! Honestly, I forgot we had such a fast setting. Almost all customers use 10V/us setting. 
The DRV8889-q1 can absolutely be used for HUD, but it is an open-loop stepper. It can report stall if there is an obstruction or the HUD hits an end stop, but there is no absolute reporting of position/angle. This would require an external encoder or potentiometer that could give position information. There is no stepper device on the market that reports absolute position. All will require an external observer (encoder, etc) to report this.
Regards,
Ryan
