7 Series FPGAs

[yhubert]

Hi,

I did not really get to know what are the FBG and FFG packages, and the differences between both of them.

I'm thinking about using a Kintex-7 900-pin 325T, but I don't know what is the package I 'd better choose.

Is there any special advantage of one of them in term of cost, speed, PCB mounting? Is there one of them targeted for a special application?

I need some help to properly choose the device. Any good documentation, link?

Thanks.

[austin]

y,

http://www.xilinx.com/support/documentation/user_guides/ug112.pdf

Flip chip packages have superior signal integrity (our patented sparse chevron technology).

Wire bond packages are less expensive, but may not be able to operate at high IO speeds (transceivers, memory interfaces), as have as many interfaces operating at the same time.

So, for highest transceiver speeds, and highest memory interface speeds, and use of all IOs at moderate IO drive strengths, flip chip is needed (almost surely).

There are also codes that tell you if the package uses lead solder, or non-lead solder bumps (for ROHS requirements where applicable).

[mcgett · Accepted solution]

I'm not quite sure hy Austin discussed flip chip vs wire bond, since both the FB am FF packages utilize flip chip technolog. The main difference between the two package types are cost with the FB, bare die, version produced with the heat spreader top and with fewer package layers to save cost. Theses difference need to be considered in your system design. The bare die version will likely need a heat sink to keep below te required junction temperature, but the good news is that thermal coefficient between the die and he heat sink will be lower than with the heat spreader. The change in the package substrate layers means that the FB version would be used for lower performance systems due to lower max MGT data rates and lower SSO allowances than the FF version.

[zhendon]

Y.

You may refer to UG475's appendix B for detail information about new FBG package.