AnsweredAssumed Answered

We found the AGC of AD9364 have a phase reverse problem,

Question asked by liuheng on Apr 14, 2017
Latest reply on May 4, 2017 by Vinod

            We found the AGC of AD9364 have a phase reverse problem, the detailed description is as follows:
Send Tone signals using internal BIST, AD9364 configured for AGC Slow tracking mode, FULL Table model, gain wasthe default configuration, do not make changes.Adjust the size of the received signal, makes the Index of AGC adjustment, when the Index pointer at 0x22 and 0x23 change, found out the ADC I Q signal phase turned over 180 degrees.
Further found that:
1. the Index pointer at 0x22 and 0x23 changes, the overall gain change is 1dm, but each unit gain change is very big, namely LNA gain change from 3 to 14, has jumped 11 db.Cause I Q phase reverse it.
2. when the signal energy to fall in this position, AGC in volatile, namely the Index pointer at 0x22 and 0x23 change back and forth again and again;And other energy, AGC pointer stable, stable after won't change.


 

 

Outcomes