ADRF6720 EXT LO INPUT Impedance

Hi Chris,

The LO inputs are 50 ohm differential inputs.

On the AD9144/ADRF6720 eval board the LO input balun is 1:1 so it should translate a 50 ohm single ended impedance to a differential 50 ohm impedance.

Regards,

Liam

Thanks Liam,

Well, it is what I thought but by opening the layout of AD9144-M6720-EBZ, I can see the balun followed by 100Ohms differential pair (J18 connetor), is it a mistake then?

Thanks again,

Best

Chris

Hi Chris,

On the layout I only see spaces for the series capacitors and the balun before it goes to J18 SMA connector

This is the layout I am looking at:

ftp://ftp.analog.com/pub/HSSP_SW/HSCDAC/Documents/AD9144/AD9144-ADRF6720-EBZ%20RevC.brd

Hello Liam,

I am looking at the same layout. If I am correct, the differential impedance after the balun is 100Ohm.

Best,

Chris

Chris,

I'm afraid I don't understand. You said " I can see the balun followed by 100Ohms differential pair (J18 connetor)" but there are no resistors between the balun and the J18 SMA connector.