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TRF371125EVM: baseband amplifier not working for the evaluation board

Jooeun Lee
Prodigy 10 points
Part Number: TRF371125EVM
I followed the instruction for the EVM test in the datasheet.
The current that the board runs is 290mA instead of 385mA in the datasheet.
When I checked using a spectrum analyzer, the mixer itself worked, but the BB amp did not.
The gain does not change when I change the "BB Gain" in the software.
I hope I can exchange this board for a new one.
  • 0
    TI__Guru 69754 points

    Hello Jooeun,

    You will need to contact TI customer service for exchange. I am not sure how I can help you.

    However, perhaps we can do some debug? If you can try to probe the GPIO pins for the fast gain change to see if they are at the right level of CMOS input, and check the gain again, I think this will help move things along. Could you please try this?

  • 0 in reply to Kang Hsia
    Prodigy 10 points

    Hi Kang,

    I checked the GPIO pins Gain_B0,1,2.

    When the EN_FastGain is off, the gain difference when BB Gain=24 and BB Gain=0 is only about 3dB. 

    It should be 24 dB. 

    Same when EN_GastGain is on. 

    I had SPI gain register programmed to 24, and changed the Gain_B0,1,2.

    The largest gain difference was about 3dB. 

    I think what is happening is that the PGA amplifier in the chip is not working at all. 

    Only the 3dB BB attenuator seems to work. 

    When I enable the 3 dB attn, I see a 3dB drop. 

    I will contact the TI customer service for an exchange.

  • 0 in reply to Jooeun Lee
    TI__Guru 69754 points

    Hi Jooeun,

    You can request exchange of EVM. However, I do not believe it is a hardware issue. Rather, you will need go through the user's guide to ensure the programmed gain is actually programmed correctly. Also, you will need to ensure ESD safety is done correctly.

    I will approve the exchange of EVM on this.