Forum Discussion

Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
12 years ago

cyclone iv LVDS

Hi All, In one of our project we are using cyclone iv gx FGPA and AD9228 adc. Ad9228 operates and 1.8v and it has LVDS interface. FPGA's VCCIO is connected with 3v3. I hope this doesn't create ...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
12 years ago

Refer to the "LVDS I/O Standard Support in Cyclone IV Devices" section of the "I/O Features in Cyclone IV Devices" document. Page 6-29:

http://www.altera.com/literature/hb/cyclone-iv/cyiv-51006.pdf (http://www.altera.com/literature/hb/cyclone-iv/cyiv-51006.pdf)

This discusses the Cyclone IV's requirements for terminating 'true' and 'emulated' LVDS signals. This is relevant depending on the I/O bank you connect your LVDS connections to.

Use this information in conjunction with the datasheet for the ADC and you should be able to establish whether or not you need ac coupling caps - I don't think you will. :)

Cheers,

Alex