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Platform forum

ravi , 06-15-2018, 12:40 PM

I want to develope a high speed ADC based board. It is clocked by a clock source of 1.5 GHz . I want to know can I use fr4 material for PCB?.

robertferanec , 06-17-2018, 01:49 PM

We have used VT47 in some of our CPU boards. I think that material is using "High Tg FR4.0"


The CPU boards are running high speed interfaces such PCIE, no problems. But, we have done a lot of testing.

Paul van Avesaath , 07-02-2018, 01:33 AM

I do a lot of 3Ghz signaling (SDI) on FR4 and that works fine, but it has its drawbacks you will experience some loss if you use long traces.. if you are going to use long traces (above 5-10 inch or so) i would recommend using FR408HR (which is the High Tg robert mentioned) or Isola variant depending on the manufacturer. If you want to go really fancy Megtron 6 is the way to go, but that is way way overkill for your scenario.
but if you are designing a board that has connectors close to the ADC FR4 will work fine.(i have some design upto 12Ghz running on FR4) but that is on its limits mind you...

Just make sure that you implement the correct impedance that is the main goal.. so when you go to manufacturer the PCB make sure match impedance option is set to enable..
also if you are using the ADC input on a longer trace, make it on an internal layer. put shielding around it and match impdance as close as possible)

robertferanec , 07-02-2018, 04:56 AM

Thank you @Paul van Avesaath