Hi-
I was perusing Allegro's site -- wouldn't their: 5810-F BiMOS II 10-Bit
Serial-Input, Latched Source Drivers with Active-DMOS Pull-Downs, fit
the bill for driving your LED display?
David

Josh Koffman wrote:

> Could you replace the discrete darlingtons with an array? Might be
> easier if you didn't have to solder each individual transistor.
>
> Josh
> --
> A common mistake that people make when trying to design something
> completely foolproof is to underestimate the ingenuity of complete
> fools.
>         -Douglas Adams
>
> Jinx wrote:
> >
> > > I have built an 8 x 128 leds designs as a matrix display,
> > > the rows [8] goes to rb0  to rb7 then the columns goes to the
> > > ra0 to ra3 through a cascade demultiplexer
> >
> > It sounds very similar to mine, except I use transistors for
> > drive. Without them it would be very dim. I have to disagree
> > slightly with others' comments about the required power.
> > Although this uses normal 3mm LEDs it is quite bright and
> > uses only 40mA (surprised me !!)  For 5mm ultrabrights, I
> > agree, the power consumed will be higher, but what I found
> > illustrates that it can be done at lower power (battery supply
> > was a requirement). This one is strobing at 200Hz, based
> > on a timer IRQ. It's a work in progress (displays messages
> > but the s/w is unrefined), so can't help much further
> >
> >
>
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