5 TX Mode Does Not Work as Expected

  1. Have you checked the proper connection of the external components?
    • Are the antenna or the analyzer connected?

    A bad connection can lead to a drop in the output power or a total loss of the signal.

  2. Are you using the device in a 3V or 5V application?
    • Have you connected the 3V to VS_PA?
    • Have you set the correct VS_PA setting in the EEPROM configuration?

    Depending on the product, it might be necessary to define the power supply level in the EEPROM configuration.

  3. Have you measured the current consumption, and what is the value?

    An incorrect current consumption can be an indication of an incorrect mode.

  4. Have you triggered VCO tuning during the start-up of a mode?

    VCO tuning is required to ensure that the PLL is able to lock under all conditions.

  5. Do you use the Buffered mode?
    • Have you set the right buffer threshold values in EEPROM?
    • Have you loaded the SFIFO and DFIFO with data?
    • Have you followed the SFIFO guidance?

    In Buffered mode, it is required to load the transmission data into the internal buffer. Also, the start conditions must be set correctly.

  6. Was there a receive event prior to the transmission?
    • Have you read all the data from SFIFO upfront?

    Any data from an earlier reception might still be present in the buffer if not accessed earlier. In such a case, the transmission might be corrupted. Therefore, it is recommend that the buffer be cleared prior to using it for the transmit function.

  7. Do you use the Transparent mode?
    • Have you added the data signal to the TMDI pin?

    Depending on the modulation, no RF signal is present as long as no signal is present at the TMDI pin.