Shazia,
Jeff Brower <j...@signalogic.com>
wrote:
Shazia-
> It is 256 BGA package ( 1.27mm)
Is
this Rev D C6711? Or earlier? You should be using at least Rev D, as previous versions are not recommended for new designs. Rev D has a 272 pin BGA package, same as C6713.
I don't have any experience
with BGA socket. I might guess it would go Ok if the quality of the socket
is good and the ball grid array is no more than 2 mm extra distance from
the board pads.
But one thing I would suggest you check carefully
when you first debug with a socket is Vcc core noise and heat dissipation.
The D rev has 16 Gnd pins in the middle of the chip, in addition to various
Gnd pins interleaved amoung the outer rows. Initially, with Rev A-B, those
Gnd pins were not there -- TI had to add them to achieve the desired
clock rate + Vcc core ripple specification + heat dissipation. So if you
are using revision less than D with a socket, this could be an issue.
Why not build up 2 PCBs
for debug -- one with socket and one without?
-Jeff
>
Jeff Brower wrote: > Shazia- > >> We r
customizing the DSP board for our application. We have designed the board
and now we need to order for PCB. I need to know that, will it make any
difference, if we mount the DSP in a socket soldered on baord instead of
soldering the DSP directly on board???? >> Please get back with me
ASAP. > > What is the DSP package type? > >
-Jeff
Jeff has some good suggestions. I have used sockets with 6211, 6711,
and 6713 devices [including mounting sockets on TI's assembled 6711
DSK boards <this is not for the 'faint at heart' or
impatient>] successfully. The only problems that I have
experienced have been manufacturing related [99% of the BGA contacts were
soldered instead of 100%]. This is usually caused by a job that is only
one or two boards and the 'assembler/manufacturer' not setting up a
proper solder profile for the socket being used.
My advice is to try not to use socketed DSPs as part of a plan.
Normally solder the DSP and use vias to make all non power/grd signals visible
on the opposite side of the board. If you can, build 3 initial bring up
boards [though two will work] - never use one unless you are very experienced
with the hardware. If boards are large and expensive, only stuff the
'heart of the system' on a couple of boards to get them up and
running.
Good Luck,
mikedunn
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