1 Reply Latest reply on Jan 13, 2020 1:27 AM by GaneshD_41

    CYBLE-416045-EVAL VDD 5.0V instead of 1.8V

    GuNo_288966

      Hi,

      I have a CYBLE-416045-EVAL board. According to the schematics, the voltage for the PSoC6 BLE module can be adjusted by setting or removing the jumper J2.

      The documentation says: jumper short => 3.3V, jumper open => 1.8V.

      I have verified that with the datasheet of the TPS735 voltage regulator, everything looks ok.

       

      However, what I observe is:

      jumper short => VDD=3,3V (measured between TP3 and TP2)

      jumper open => VDD jumps up to 5V! This is out of specs for the CYBLE-416045-02 module.

       

      I have then measured the voltage at the FB pin (pin 2) of the voltage regulator.

      Jumper short => 1.220V (close enough  to 1.208V, ok)

      jumper open => voltage goes up to 2.44V (FAIL), should stay at 1.208V.

       

      It seems that the voltage regulation of the TPS73 fails.

       

      I have looked at all resistors and capacitors, everything looks like it should be according to the schematics.

       

      What is wrong, what should be changed to set VDD to 1.8V?

       

      Update: It seems that the problem only occurs when the jumper J2 is pulled while the board is powered.

       

      Regards,

      Guenter