[SI-LIST] Re: Decoupling capacitors
- From: "Muranyi, Arpad" <arpad.muranyi@xxxxxxxxx>
- To: <si-list@xxxxxxxxxxxxx>
- Date: Tue, 17 May 2005 10:28:21 -0700
While there may be a lot of truth in the writing of Stefan
below, I wonder whether what he writes is the main or only
reason.
Think about it this way: The package acts as a bottle neck.
You need to push a lot of current through it and do it so that
it can have large sudden changes. No matter how much a mother
board maker is willing to spend on their design, there is a
limit for how much current can be forced through the bottle
neck. Beyond a certain point, no matter what you do on the
mother board, you will simply not be able to push more current
trough a low cost package. So my gut feeling is that Intel
may not just do this to be nice to the mother board makers,
and thereby win more customers for our CPUs...
Arpad
--------------------------------------------------------------
-----Original Message-----
From: si-list-bounce@xxxxxxxxxxxxx [mailto:si-list-bounce@xxxxxxxxxxxxx] =
On Behalf Of steve weir
Sent: Tuesday, May 17, 2005 9:38 AM
To: Stefan Ludwig
Cc: Ken Cantrell; Larry.Smith@xxxxxxx; joepaul@xxxxxxxxxxx; =
si-list@xxxxxxxxxxxxx
Subject: [SI-LIST] Re: Decoupling capacitors
Stefan exactly! The oppressively competitive computer market has forced =
Intel to design for total system cost. It's a lesson that many other =
chip=20
builders need to learn well if they expect to succeed in a market that =
is=20
becoming more consumer electronic, sic low total cost, oriented.
Regards,
Steve.
At 06:27 PM 5/17/2005 +0200, Stefan Ludwig wrote:
>A slightly different angle on this is the following:
>
>Intel's 90nm processors consume 130W these days (desktop and server=20
>parts). That can be more than 100 Amps! You simply can't afford a =
"cheap",=20
>"un-bypassed" package with this sort of power and current requirements. =
>Once you bypass to the max on the die itself and in the package, you =
end=20
>up with a lot less stringent requirements on the PCB.
>
>A nice side effect of the above and a requirement from Intel's =
customers=20
>is that their processors need to run with the cheapest possible boards=20
>produced by the customers' contract manufacturers. Intel must engineer =
a=20
>rock solid chip/package solution, which then allows their customers to=20
>have a simpler board structure and cheaper bypassing. For a while, =
Intel=20
>delivered their processors in the form of cartridges, so that even the=20
>least capable customer can build a PC board that still works. It had =
the=20
>processor die and cache SRAMs on it, as well as lots of bypass caps.
>
>Nowadays, they sell you boxed chips, with the heat sink and cooling =
fan,=20
>so you don't blow up "your precious!"
>
>Stefan
>
>"May you live in interesting times!" - Chinese curse (<- NOT, as it =
turns=20
>out if you google for it.)
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