AMC1305L25: LVDS signal amplitude too high

Jonas Gründler

Part Number: AMC1305L25

Hi all

According to the datasheet this IC should have an LVDS output with a differential amplitude of 350mV.

Onn my setup in the lab I measure a differential Amplitude of around 730mV which is obviously too much.

I terminated the signal with 100Ohm at the FPGA side as written in the Datasheet.

Below is a oscilloscope image of the LVDS signal.

Could it be due to the supply voltage and scale with the input?

Something like: 3.3V supply => 350mVpp

5V supply => ca. 720mVpp

Has anyone an idea about this behavior?

Thx in advance,

Jonas

0 Tom Hendrick over 2 years ago

Hi Jonas,

The CMOS output version of the AMC1305 does scale with the voltage rail, so I suspect the LVDS version may as well. We'll confirm that for you.

0 Jonas Gründler over 2 years ago in reply to Tom Hendrick

Thanks for the fast reply.

Looking forward for your answer.

This could be the reason for the high amplitude. If this is not the case I'wondering what could explain these measurements.

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