LMX1214: Power dBm

Nandini Muralidharan

Part Number: LMX1214

Tool/software:

Hi,

I have a differential 225MHz clkout to FPGA. LVDS Input side AC-coupling requirement in FPGA is highlighted.

What is the power out dBm need to choose for clkout to meet the FPGA input voltage requirement?

Thanks

0 Noel Fung 5 months ago

Hi Nandini,

We will check in the lab tomorrow.

0 Noel Fung 5 months ago in reply to Noel Fung

Hi Nandini,

I assume you are referring to AUXOUT.

PWR setting = 0 or 1 meets FPGA requirement. PWR =0 voltage swing is 372mV. PWR=1 voltage swing is 450mV.

0 Nandini Muralidharan 5 months ago in reply to Noel Fung

Hi Noel,

No - I mean the CLKOUT only not the AUXOUT. Input clk is 1800MHz for CB. We can divide by 8 and take it out as 225MHz for the FPGA.

FPGA accepts AC-coupling for LVDS. Hence we plan to connect the CLKOUT to FPGA.

What would be PWR setting in that case?

Also, can you recommend the proper termination for CLKOUT while connecting to FPGA?

0 Noel Fung 5 months ago in reply to Nandini Muralidharan

Hi Nandini,

If you use CLKOUT, you have to AC-couple it to the FPGA.

PWR =2 voltage swing is 420mV.

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