There's any way to mute the AD9364 tx output during the initial calibration phase to prevent the output of unwanted spectrum? I've tried to set the TX att to max level after the GPIO reset but seems that not produce any result..
Internal to chip there are no Options , except to disable calibration. You can switch Off front end circuits (PA /LNA ) during initial cal time , if provision is there. PA /LNA
thank you for your answer.
We actually need calibration, so disabling it is not really an option for us. Because of this, we have been thinking about possible workarounds.
In our application, the second output TxB is unused, so on the board the associated pins have been both directly connected to the power supply net (+1.3 V), as suggested on the device datasheet. Of course, from the RF signal point of view, this is equivalent to say that these pins are short-circuited.
So, my question is: would it be of any harm for the device to let it perform all the initializations on the output TxB (i.e., driving those emissions on an unused, zero impedance output) by properly controlling the output mux, and then switch it back on TxA when everything is up and stable?
Many thanks for your support.
Calibration has to run on the same path TX1A , B or Tx2 A , B for finding the errors and correct them , Running on one and applying on another will not help.
from UG570. :The Tx quadrature calibration stores a separate set of calibration results for the Tx_A and Tx_B output paths. If using both the Tx_A output and the Tx_B outputs, run the calibration twice, once with each output path selected.
Init calibration is done during power up only. Do you have issues for one time power up cal tones.?
Is it possible to power on PA with some delay or switch off PA during initial calibration time.?
Vinod, thank you for your explanation.Of course there are some reasons why we would like to be sure that our modulator board doesn't output calibration tones by itself, rather than rely on the switch off of the PA.From your answer, it seems clear that there's no way to prevent those unwanted output calibration tones from the AD9364 itself, so we're planning to add a proper attenuation circuit externally.
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