P9242-R Wireless Charger not working

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

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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!

Hi,

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?

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

Hi Cwern,

1. What is the Rx used to test the Tx?  what is the load current of the Rx when the issue occurs?
2. What is the Tx coil part number?
3. Can you measure the temperature at the thermistor when the over temp shutdown is triggered?
4. Can you probe below signals before the power transfer until the over temp is triggered?

                TP314(TS), TP306 (LDO33); TP505 (coil1); Input current of the Vin+ and Vin+

5. I can't open the layout.  Can you send me the PCB layout in PDF (similar to the section 5_Board layout in the REN P9242-R EVK User Manual)?

Thanks!

Hi Cwern,

1. What is the Rx used to test the Tx?  what is the load current of the Rx when the issue occurs?
2. What is the Tx coil part number?
3. Can you measure the temperature at the thermistor when the over temp shutdown is triggered?
4. Can you probe below signals before the power transfer until the over temp is triggered?

                TP314(TS), TP306 (LDO33); TP505 (coil1); Input current of the Vin+ and Vin+

5. I can't open the layout.  Can you send me the PCB layout in PDF (similar to the section 5_Board layout in the REN P9242-R EVK User Manual)?

Thanks!

Hi,

sorry for the late response.

1. Rx used is P9415, issue is independent of load current
2. Tx coil is custom
3. Voltage at the pin of the thermistor is dropping below 0,6V when error is triggered (temperature is also high at this moment, for testing I used a hot air soldering station). After the temp shutdown voltage at temp pin is returing to normal value
4. See attached image, Channel 1 is TP314, Channel 2 is TP3069, Channel 3 is TP505, channel 4 is Vin+ 
5. See attached PDFs

20914_IndiumTx-01B_Top.pdf 20914_IndiumTx-01B_Inner2.pdf 20914_IndiumTx-01B_Inner3.pdf20914_IndiumTx-01B_Bottom.pdf 

Just pushing the thread up