Can I use the ADAQ23878 with a 1.8V LVDS interface?

Hi,

RegineGarcia will look into this and get back to you.

Regards,
Jo

Hi Uboti,

The ADAQ23878 can't be used with a 1.8V LVDS (FPGA) when its VIO is set to 2.5V because the LVDS logic levels generated by the FPGA might not be fully compatible with the levels generated by the ADAQ23878. This is because LVDS outputs operate in VCM and differential swing defined by the 2.5 VIO Supply.

To address your concern, you may utilize a level shifter or a translator to shift the LVDS levels from 2.5V to 1.8V which would ensure compatibility.

Aside from this, you may explore other FPGAs that support wider LVDS input ranges.

You can adjust the VIO for other ADCs, but for ADAQ23878 you can't (see below for the specification).

Thank you!

Regine

Thank you for your reply.
Q1: Does ADI sell LVDS level shift ICs?
Q2: I'm not familiar with LVDS, so I may be wrong, but I looked it up and found that LVDS also has AC coupling. Can it be connected to a 1.8V system with AC coupling?

Hi Uboti,

Yes, ADI sells level translators. You may refer to this link to view all parts available: https://www.analog.com/en/parametricsearch/13009

I wouldn't recommend using AC coupling as this would introduce noise to your system from the parasitics of the passive components needed with AC coupling.

Thank you

Regine

thank you for your reply.

 https://www.analog.com/en/parametricsearch/13009

I looked at the link above and the level shift IC was for other standards such as I2C. Which one is compatible with LVDS?

Hi Uboti,

You may select Level Translation under the High-Speed Logic Function filters to get the LVDS compatible translators such as the ADG3308 Series or MAX9376.

By the way, what application are you planning to implement this?

Thanks,

Regine

The application will be a thermal imaging camera.
The signal will be received by several ADAQ23878s and connected to a downstream FPGA via LVDS.
Thank you for the introduction to level shifting.
The FPGA's LVDA I/F is 1.8V, so I don't think the MAX9376 can be used at 3.3V.
I will check the datasheet to see if it can be used with the ADG3308.