Re: tiny inductor with every bypass cap?

"Talal Itani" <titani@[EMAIL PROTECTED]
> wrote in message
news:QJB7k.965$9J.528@[EMAIL PROTECTED]
>
> >
> > It is not a big deal to lay out the board for TMS28xx. Two layers work
> > fine. With 28xx, the very im****tant thing is the power sequensing on
> > startup and shutdown.
> >
> >> The inductors on this design are pretty bizarre and are likely not
> >> even used on the real board.
> >
> > Indeed. Especially as the power pins of the chip are supposed to be
> > connected directly.
>
> Yes.  Bizarre is the right word.  Two layers work fine for TI 20xx?  No
> ground plane, no voltage supply lanes?

It depends.
Really nothing special is required for TMS28xx for the EMI and the signal
integrity purposes. However if the board is supposed to sustain the BCI
test, then  you will have to use four layers or more.

>
> What about using one of TI's power ICs, with 3.3V  1.8V and Reset
Generator?

Don't know about the dual regulators, never used those. Check the
sequensing
specs very carefully; it could be the false states at the outputs at
startup/powerdown.

Vladimir Vassilevsky
DSP and Mixed Signal Consultant
www.abvolt.com