BQ24133: BQ24133 : Please help check the schematic

Dear Star,

What happens if you remove the 15 V pullup to /BATDRV? The voltage of the /BATDRV pin is controlled by the charger and does not need to be pulled up. Can you connect the gate of 5Q9 directly to /BATDRV with just a 1kOhm and see if the part can turn on? I am worried that if the charger tries to output a low on /BATDRV current will be driven into the charger. In addition, this pull-up changes the break-before-make logic of the adapter presence and the input FETs.

Thanks,

Mike Emanuel

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Hi Mike Emanuel

Thanks for your reply.

I removed the 5D11 and 5R9 in the schematic, and did not use BQ24133 to switch the power supply, so /BATDRV is not actually connected.

Is it feasible？

Thanks

Star

Dear Star,

You need to keep 5R9 and directly connect it from /BATDRV to the gate of 5Q9. The resistor 5R82 should not be populated.

Thanks,

Mike Emanuel

Please click "This resolved my issue" button if this post answers your question.

Hi Mike Emanuel

Thanks for your reply.

This time I used the 5V input first, the 5V input is ok.

but when increased to 12V, the VREF can output 3.3V, but after a while, the chip is still smoking, the reason still not found.

Please give some suggestion.

Thanks

Star

Dear Star,

Can you please include some waveforms of PVCC, SW, SRN, and the charging current in both cases?

In addition, it looks like there may be some problems with the layout. The sense resistor is not right next to the inductor output.

What happens when 15 V is applied now?

Thanks,

Mike Emanuel

Please click "This resolved my issue" button if this post answers your question.

Hi Mike Emanuel

Thanks for your help.

Please help check the waveform as below. Because the charger is abnormal they did not connect battery or load.

6330.waveform.docx

Thanks

Star

Star,

I am going to need more specifics as to what caused the chip to burn. Did you apply 12 V, wait for a while, and then the chip burned? Or did it burn immediately? Does this problem happen with a 15 V input? What was the battery voltage at the time of burning? Any and all setup remarks will help to assist this debug.

Thanks,

Mike Emanuel

Hi Mike Emanuel

Thanks for your help.

Circuit is normal now, resend the board to patch, before burning reason should be welded at the bottom of the plate of poor contact, I can now charge, the charging current and charging status are all right, but the whole process charge BQ24133 was very hot, the temperature of the large current when charging the whole board has 60 degrees, the charge of the chip temperature is reached more than 90 degrees, I now the board is two layer board, the board size is 48 mm * 48 mm, please have a look at what's in my PCB cooling problems lead to chip, so hot, thank you very much!Attached are the schematic diagram and PCB diagram. In the actual circuit, 5R82 is not welded. Sorry for the trouble!BAT_CHARGE.pdfSOLASE_CHARGE-V1.0-20200520.pdf

How much current are you trying to input to the board (from the combination of charging and your system load)? If you are inputting your 15 V at your INDPM of 4 A, that is 60 W. Please make sure your power traces can handle the current requirements of your charging load and system load. In addition, please make sure you have an adequate ground plane to dissipate this heat.

It appears that the thermal pad of the IC is not connected directly to ground through vias. The datasheet states the critical need for vias on the thermal pad to dissipate heat from the IC.

Thanks,

Mike Emanuel

Please click "This resolved my issue" button if this post answers your question.

Hi Mike Emanuel

Thanks for your help.

  I've now set the input current to 2A， and the output current to 1.6A。The result was slightly improved by the drop in the current。In fact, the bottom pads of the chips are perforated，And I also added a piece of cooling copper at the bottom of this experiment，But the chip temperature is very hot, the temperature of the entire board can reach 40 to 50 degrees，Please refer to the attachment for the experimental results！Please help to see where else the temperature is so high. Is there a problem with the circuit principle or PCB board wiring? Thank you very much!新建 Microsoft Word 文档.docx