Hello,
I'm having trouble with my P9242-R based wireless charger that I designed for a client. The chip in question is this:
https://www.idt.com/us/en/products/power-management/wireless-power/wireless-power-transmitters/p9242-r-wpc-122-compliant-wireless-charging-transmitter-15w-applications
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?
Hello avimurali! How's it going? Have you identified the other parts of the circuit that are also heating up? I do hope you could wait for others who are experts on this to give you a definite answer. You might want to interact with the poster from this thread: http://renesasrulz.com/general/f/general---forum/15690/wireless-charger
All the best! Sai RenesasRulz Forum Moderator https://renesasrulz.com/ https://academy.renesas.com/ en-us.knowledgebase.renesas.com/
Hi everyone,
we are experiencing similar problems with our boards. Once the IC is detecting over-temperature, the Q_DRV1 transistor is swichting on and stays that way indefinitely.
How did you manage to solve this problem? Any advice?
Thank you!
Hi Cwern, Can we see your schematics, layout and BOM?
Hi,
please see the attached files. We know there is a layout error concerning the measurement of VBRG_IN, which we corrected on the board. The rest is designed according to your reference board.
P9242_BOM.pdfP9242_Gerber.zipP9242_SCM.pdf
Hi Cwren, after fixing VBRG_IN did issue persist?
Hi, yes the issue persists.
Hi Cwern,
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?
Thanks!
Tri said: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?
TP314(TS), TP306 (LDO33); TP505 (coil1); Input current of the Vin+ and Vin+