P9242-R Wireless Charger not working


I'm having trouble with my P9242-R based wireless charger that I designed for a client. The chip in question is this:


I used the exact same circuit given in the official datasheet. Followed the layout guidelines.

The issue I'm having is that the board powers on, green LED flashes for a second, then the red LED starts flashing at 4 Hz indicating a fault.

I tried getting the status register value via i2c bus and it seems like it's indicating a "over temperature fault". The problem is I kept getting different values while trying to read the status register via i2c. But the number "6" kept coming up which might indicate the temperature fault according to the datasheet.

Upon further investigation, I also found the Q6 FET to be insanely hot to the touch. I replaced the FET, and yet the new FET continued to be super hot to the touch. I checked for shorts but couldn't find any. The Q6 FET is indicated in the picture below.

Any help would be appreciated! Am I missing something?

Parents Reply
  • Hi,

    1.  Can you read 0x6E0 and 0x6E1 when the issue occurs?

    2.  Does it happen when  the Tx is in power transfer or not in the power transfer?

    3. What is the voltage level of TP314 (pin 30 (TS))?

    4. Can you probe TP327 (SW_BRG2) and TP507 (gate of T504) in 1s/div?

    5. What is the FW version?

    1. 0x6E0 is showing 0x02 or 0x04; 0x6E1 is showing 0x06
    2. It is happening during power transfer
    3. Voltage level is 2.1V after initially triggering over-temperature at 0.6V
    4. See attached image. Red is TP327, blue is TP507  
    5. FW version is major 0x06 minor 0x18