Re: A3977 Microstepping Driver PCB Update

I had problems with the 3977, sucked wind every time I tried to go
above about 1.5 ampers, on a particular stepper that I wanted to use.
All other step motors I tried worked great. (at least a dozen
different motors).

All I could come up with that was destroying the chips was perhaps
too low of a winding inductance, causing too fast of a rise time that
the chip could not handle.

I know that some driver chip manufactures specify minimum inductance.
Allegro does not.

Some other motors that I tried, even though they had lower
resistance, had higher inductance (good performance).
The 3977 stayed cool as a cucumber at 2.5 amps.

It was a shame, cause the 3977 does have some nice features.

I ended up using ol-reliable... "Gecko".

Tom M.

> circuit boards for Allegro's new A3977 chip, but I'd like some
> feedback from you folks. (almost) current info is posted on my