AFE7444EVM: IQ imbalance (DAC mode)

Zoran

Part Number: AFE7444EVM

Hi TI support,

We succeeded to perform experiment where we connected AFE7444EVM with ZCU102.

In Tx mode (DAC mode6) we send I & Q signals (cosine and sine, respectively) and we noticed large I/Q imbalance (please see pictures attached)

The first picture is I/Q -> cos, sin

The second picture is I/Q -> cos, -1*sin

Is there any option in AFE GUI how to fix this issue, or is there any other way to fix this inside AFE7444 chip?

NCO frequency is set to 1500MHz, baseband frequency of sin/cos signals is 5.76MHz

Please advice,

Thanks in advance,

Zoran

over 1 year ago

0 David Chaparro over 1 year ago

TI__Genius 16821 points

Hi Zoran,

One thing to check is if the FPGA to AFE lane mapping has been taken care of. On the EVM to ZCU102 connection the lanes will not be mapped one to one, so this could cause an issue with the DACs not getting the correct I/Q data.

Can you check this in your design?

Regards,

David Chaparro

0 Zoran over 1 year ago in reply to David Chaparro

Prodigy 30 points

Hi David, thank you for suggestion, but can you explain a little bit how crossbar section in AFE GUI should be used?

Also if there is something else that we should look to be sure about lane mapping on the AFE side?

Best,

Zoran

0 David Chaparro over 1 year ago in reply to Zoran

TI__Genius 16821 points

Hi Zoran,

Wer recommend updating the mapping in the FPGA. Can you share the pin assignments for the SerDes lanes in your design?

Regards,

David Chaparro

RF & microwave

RF & microwave forum

AFE7444EVM: IQ imbalance (DAC mode)