Re: 8-wire stepper: series is 1/2 the amps.Strange but True

I double checked Allegro's site.

these are limited to tiny steppers with a current draw of 750 mA.

http://www.allegromicro.com/press/02_3967.htm

With that small a load, I don't think power and frequencies will be a
problem.

The simplest way to mount is to put them on a Surf Board (digiKey)
and then put that into a standard thru hole board.

the data sheet for the chip shows the recomended method of using
periferal chips.

http://www.allegromicro.com/press/02_3967.htm

Dave


--- In CAD_CAM_EDM_DRO@yahoogroups.com, Charles Knight <charles@i...>
wrote:

> Stepper Driver circuit design
>
> I have gotten my samples from Allegro, and they're the 3967 single

chip

> bipolar stepper translator/driver. Nice chip...inconvenient

package for

> a homebuilder (24 pin SOIC), but a nice chip nontheless. that's

what

> PCB CAD libraries are for.
>
> So...I have a chip, a power supply, and a stepper motor. Now

what? ;-)

>
> No...I'm not starting out quite that basic -- the circuitry is not

going

> to be a big problem, but a motor is an inductive load, which

sometimes

> complicates things. I assume there will be backcurrents to deal

with,

> possibly interference from traces laid parallel to each other at

certain

> frequencies, etc. I understand the parallel port can operate at

50KHz?

>
> So...any tips on stepper driver board design, from those who have

done

> it? Do I need to isolate the grounds for the various parts of the
> circuit? Diodes to prevent backcurrent from reaching the chips?

That

> sort of thing. I have only the white sheets from Allegro, at this
> point, on which to base my design.
>
> Has anyone ever designed a circuit based on this chip? I

understand

> it's new...single chip translator and microstepper for bipolar

drives.

> If I can get it to work, I think it'll be nice.
>
> THANKS!
>
> -- Chuck Knight