CC3351: When repeatedly tested the BLE power, the power fluctuated significantly.

Any update?

Hi：

Has anyone been watching this issue? It has been 10 days already.

Hi Yixiong 

per talked yesterday, did you get a stable TX power when you use the packet length to 37 (0x25 in HEX)? or change to another equipment, e.g. Spectrum analyzer with 1MHz RBW. 

BR. Albin

Hi Albin

   I did as you say，used the packet length to 37, and used the CMW270 for test, the packet length on CMW270 also set to 37. But The problem still exists. You can see my test date.

Hi

Any update？7 days have passed.

Hi,

Apologies for the delay. I will have the hardware team look into this for you. 

Hi Yixiong,

Can you describe how you are measuring the tx power here? 

Are you using the Meter VSA that you showed in the other thread or some other machine?

We do not see this kind of tx power fluctuation on our side.

Regards,

Jonathan 

Hi Jonathan Cohen

     I have recorded the video of my test, This will help you have a more intuitive understanding of my problem. One is test on BP-CC33X1 used radiotool, the another is test on our board card used calibrator tool. Both of them have the problem of power fluctuations. I used the litepoint test.

calibrator tool command on our board card:

Radio tool set on the BP-CC33X1

Hi Yixiong,

Thank you for the helpful video. We are still trying to replicate this issue on our side, but are unable to. Litepoint is our tester of choice and we have extensive testing on this device - we have no encountered behavior similar to this with all of this testing. 

Is the behavior with the Litepoint identical to what was observed with the CMW tester?

We matched your tester settings exactly, except for one setting that would not let us capture:

Can you adjust Pwr Detect Gap Time to 3.2 us? This was our default setting and 0 does not work for us - maybe its related.

Hi Dylan Hubbar

   I think I have figured out the reason for the power fluctuation of BLE when using the radio tool for testing. I move the jumper on the LPXDS110 (labeled TGT VDD) to the EXT, and connect the second micro-usb power to the BP-CC3351, than the power is stable.

  But I when i use the calibrator tool to test our board card, The power still fluctuates. You can get the detailed information by watching the video I sent you last week, here are my command and test step. 

Hi Yixiong,

Glad to hear this works now. 

Notice that with the BP-CC3351 you should only use the LP-XDS110ET. Not the LP-XDS110 like you have in the picture below. 

The right setup here is documented in our user's guide:

Make sure you follow this guidance.

Regards,

Jonathan 

Hi:

   OK, now the problem is when i use the calibrator tool to test our module, The power still fluctuates(No use of LP-XDS110). You can get the detailed information by watching the video I sent you last week, here are my command and test step. please take a look at this issue.

Hi Yixiong,

Lets see if there is any power fluctuations on your HW as well.

Please verify that your HW power supply can support the required current consumption according to datasheet spec. 

This is a note from our datasheet:

You should also verify that the correct voltages are reaching the correct device pins according to datasheet.

Regards,

Jonathan