LVDS resistor termination in Cyclone III

Question

Hello,

I have a design with 2 FPGA (EP3C16F484) linked together with a set of LVDS line.

I use pins in bank 1, 2, 5 an 6.

Should I place a 100ohms resistors on the receiver side, or is it included in the FPGA?

(I have search for this information in datasheet. I have undersand there is no need for resistor on transmitter, but nothing really accurate on receiver side)

Thanks

altera_forum · Answer

--- Quote Start ---  Should I place a 100ohms resistors on the receiver side  --- Quote End ---   Yes. The hardware manual is clear about this point.

altera_forum · Answer

Thanks for answering.  Please could you told me where the hardware manual is clear (is that on page 7-27)? I have miss something... and I want to read it carefully.

altera_forum · Answer

--- Quote Start ---

Thanks for answering.

Please could you told me where the hardware manual is clear (is that on page 7-27)?

I have miss something... and I want to read it carefully.

--- Quote End ---

Page 6-20 of the cyclone III handbook:

The LVDS standard does not require an input reference voltage, but it does require a

100-Ω termination resistor between the two signals at the input buffer. An external

resistor network is required on the transmitter side for top and bottom I/O banks.

Page 7-8 of the cyclone III handbook:designing with lvds

Cyclone III device family I/O banks support LVDS I/O standard. The left and right

I/O banks support true LVDS transmitters. On the top and bottom I/O banks, the

emulated LVDS transmitters are supported using two single-ended output buffers

with external resistors. One of the single-ended output buffers is programmed to have

opposite polarity. The LVDS receiver requires an external 100-Ω termination resistor

between the two signals at the input buffer.

Success, Ton

altera_forum · Answer

Hello I am Miguel and working on FPGAs for 4 years.

I recently found an doubt that I ant to confirm:

All IO banksfrom Cyclone 3 have dedicated LVDS RECEIVERS and only 1, 2, 5 and 6 have DEDICATED LVDS Transmitters right???

Thank you in advance.

Regards

--- Quote Start ---

Page 6-20 of the cyclone III handbook:The LVDS standard does not require an input reference voltage, but it does require a