Re: L297/L298 And a "correction"

Alan:

> Hi Wayne,
>
> But after you add those DACs and comparators, don't you
> increase the price ...

I don't think so.

> ... and complexity?

I guess things are more complicated. Sometimes increased
complexity does save some money.

> And a 2nd L298, it sounds like. Yes, I recall someone
> doing that.
>
> L298 DigiKey: 497-4554-5-ND $4.20
>
> LMD18245 : LMD18245T-ND $13

To the best of my knowledge the LMD18245 is just a
single H-bridge. For a bi-polar driver, you would need
two of these. Thus,

2 x L298 (Jameco: 245403; $2.95 for 1) = ~$6

versus:

2 x LMD18245 (Digikey: LMD18245-ND $13.02 for 1) = ~$26

They come in the same basic package (a MultiWatt15).

> So if you need two, it's getting closer.

Not really (see above.)

> And I think the DMOS transistors
> in the '245 might be more efficient, so less heat dissipated?

Yes, but heat sinks for the MultiWatt15 package are ~$1.

> If you have a DAC and comparator, then you might be able to
> use the ASM or C source code developed to drive the '245.
> Not that it's all that complex! Looks like the code to
> drive an old 4-phase unipolar stepper; just different
> table info!

[snip]

-Wayne