ST25RU3993 not generating RF signal on PAOUT_P and PAOUT_N (Pin No - 21 and 16 respectively). What can be the possible reason ?

[NNagp.2]

We are using ST25RU3993 IC with STM32L476 MCU. We are using the same SDK Provided by ST. But after giving the command of Start Scan in GUI(ST25RU3993 Reader Suit), we are not able to read tags. We also checked the signal on PAOUT_P and PAOUT_N through VNA. But it does not show any signal on that pins. We have designed our own PCB board as per reference provided by ST. We also debug the code using ST-Link and in st25ru3993initialize() function there is SPI connection error. But we have checked using multimeter the connection between STM32L476 and ST25RU3993 IC (SPI lines) is ok. We are using internal PA in this. Kindly help us in this problem.

[Ulysses HERNIOSUS · Accepted solution]

Hi,

which SPI error are you getting exactly, at which step? It sounds like the chip is not powered / a major issue in the SPI configuration. Please trace the SPI + /SS + INT signal while executing the st25ru3993Initialize() using a logic analyzer.

BR, Ulysses