0
\$\begingroup\$

I have followed all the guide lines for powering up the Cyclone IV. However, the 3.3v Regulator is heating too much and also the Cyclone IV FPGA. What's wrong with my schematic? Is there a problem in connecting the heatsink located below the Cyclone IV chip into 1.2v? By mistake I connected it into 1.2v line.

enter image description here

\$\endgroup\$
0
\$\begingroup\$

Internally, the pad is electrically connected to the device GND pins, so connecting it externally to anything else is a critical error.

The Intel device page has a link to a packaging spec list, that links to a packaging spec page, that links to a pinout document, that has this footnote:

(4) The E144 package has an exposed pad at the bottom of the package. This exposed pad is a ground pad that must be connected to the ground plane on your PCB. This exposed pad is used for electrical connectivity, and not for thermal purposes.

https://www.intel.com/content/dam/www/programmable/us/en/pdfs/literature/dp/cyclone-iv/ep4ce6.pdf

\$\endgroup\$
  • \$\begingroup\$ Ohhh... can I leave this pad unconnected by placing a peace of paper between the chip's pad and the pcb board's pad? \$\endgroup\$ – Alpha0 Jan 16 at 15:04
  • \$\begingroup\$ @Alpha0 You can try, but as per the datasheet in the link, it would not be in specification. It is quite possible that the chip's internals need this connection to ground (might be an internal routing issue). \$\endgroup\$ – awjlogan Jan 16 at 15:22

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.