AnsweredAssumed Answered

L6472 parameters setting

Question asked by chen.sam.003 on Oct 29, 2014
Latest reply on Sep 11, 2017 by Nathan Coon

I'm new to L6472 here, and from reading its datasheet, I think it would be a perfect fit to my application which will need to drive a NEMA34 motor to go relative high speed (such as 12 rotations per sec.). 
I've been reading AN4158 which is related to L6472 and am puzzled by
some of the concepts there, could someone help explain?



*) The concept of target switching time (it sets the target PWM frequency of the control system) is not clear to me, what's the relationship between this parameter and the step speed (or step period)? (or is there any relationship between these two parameters?)
And why it's better to have a fixed PWM frequency? is this PWM frequency the same PWM that creates the microstepped phase currents in microstep mode?
*) it seems to make auto adjusted decay and predictive current control work, 6 parameters need to be set properly: TOFF_MIN, TON_MIN, TOFF, TOFF_FAST, FAST_STEP, TSW. It was not clear to me how these six variables shall be set properly, is there any concete example of the analytical steps someone should take to set values (or a value range) for these variables/parameters?