Injector driver chips? Where?

[Martin Mayhead]

> 
> Look at national's LM1949, it is a single piece part, but is very flexible.
> It is being tested to also see if it will work as an ignition driver. Very
> flexible, and not to expensive.
> 
> Sandy
> 

Beware - this chip does not operate as a switch mode controller and so the
darlington dissipates a lot of heat! It does allow for a low part count 
solution but fixes the ratio of peak to hold current to 4.
. 
. 
. 
> >Have you checked out the L584 from SGS-Thomson?
> >You can build a complete driver circuit with one L584 (DIP16), two darlingtons
> >and a few resitors and capacitors. The L584 can be set up to use one of four 
> >diffrent load current waveshapes, including peak-hold-drop and peak-drop.
> >I don't know if the IC is easy to get hold of, or if it's still in production.
The L584 is still in production from SGS - they are not easy to get hold of
though, I typically get quoted 25-40 week lead times. This is a very flexible
chip though and because it works in switch mode the darlingtons don't dissipate
much heat (about 1/4 that of LM1949 design). It will produce some RFI because
the inductor (injector) is switched fairly fast and is on the end of a long
piece of wire (aerial). This solution allows any peak/hold ratio to be
implemented. The chip costs about 2.50 (pounds Sterling) in 25 off.

	Regards, Martin Mayhead