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From: Chuck Simmons
Organization: You jest.
X-Mailer: Mozilla 4.61 [en] (X11; U; Linux 2.0.33 i586)
Subject: Re: Future power supply concepts for automotive electronics
References: <3D878889.98EC63A6@erckert-ibe.de> <3D8E3436.32FD08A6@webaccess.net> <3D8F86FC.CBC83B71@erckert-ibe.de>
Date: Tue, 24 Sep 2002 03:44:11 GMT
NNTP-Posting-Date: Mon, 23 Sep 2002 20:44:11 PDT
> I agree staying at a low performance technology would do the job for
> many of the things you need. Unfortunatelly automotive companies (and
> they claim their end customers too) love nice gadgets with lots of
> displays, GUIs, GPS, keyless entry....
> The automotive companies managers dream of operating systems and object
> oriented programming.
> All this drains performance like hell and we end up with a power PC to
> control a simple window lift! But the shrink roadmaps of the controller
> suppliers are there and dreaming managers push design.
> Besides that there is a spare part problem. I'm sure future controllers
> will be able to emulate a let's say HC12, but they won't have the rugged
> ports of it anymore. Nobody will keep a microcontroller fab running just
> for a few million units for the automotive market while at the same time
> prices are down.
I've thought about some of the stuff you mention but there are problems
that require bridges between technologies. I am more familiar with the
mess I have to deal with in DVDs. I presently have to have +3.3 volts
(0.35 micron), +5 for some glue and +12 for motors and actuators. By
using 5 volt tolerant pads, we are OK for most of the system but the 12
volt stuff gets interesting because the 3.3 volt parts have to control
the 12 volt parts and we are eliminating glue logic as fast as we can
(it gets sucked inside of our LSI). Looking at shrinks, we get into
trouble with mixed signal parts (analog doesn't shrink). Moreover, going
to 0.18 with 2 volt power is murderous for signal to noise in the mixed
signal parts. The 12 volt supply is not going to go away in any case
because, for example, lowering the force constant of the actuators to
work on 5 volts would make them too anemic to meet bandwidth
requirements. So a shrink means I have to have all of +2, +3.3, +5 and
+12. The 5 volt tolerance has to remain however it can be done because
even after a shrink we still have an ATAPI interface (for several years
to come anyway). Another unhappy situation is that the lasers have about
a 2.4 volt drop in operation. If we get blue, I think it is even higher.
That sticks us with +5 for the lasers. It's physics.
This is a lot like the car electronics problem where you really want to
minimize chip count by shrinking and consolidating functions while
having to deal with 17 volt ugly power and controlling several amps (up
to about 75 in typical cars). You have to either proliferate chips to
keep technology optimized for the task at hand or do mixed technology
which is, to some extent, possible. The latter allows total power down
of power hog technologies while context and power up logic can be in the
less power hungry technology.
You asked about separate or on board flash because I mentioned that
practical flash life works pretty well with car life. Depending on the
ASIC vendor, it may make no difference. People do get upset about on
board memory. It is huge. It is not unusual for memory to take up most
of the chip area in a chip with MPU(s). One could argue to pull the
memory out but this increases pin count and interconnect (bad).
In any event, the goal has to be to minimize chip count, minimize
interconnect and still get the job done without compromise.
... The times have been,
That, when the brains were out,
the man would die. ... Macbeth
Chuck Simmons email@example.com
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