Hello all,
LOIN– (pin 33) and LOIN+ (pin 34) are 50Ohm each or 50 Ohm differential (25Ohm each)? Checking your eval board (AD9114/ADRF6720), it seems that it is 100Ohm diff so I want to double check with you.Thanks for your help.
Best,
Chris
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
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.
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.