Other Parts Discussed in Thread: TPS25750, BQ25790, BQ25792, EV2400, USB2ANY, BQ25750
I have purchased this EVM and designed a board around it for a consumer speaker product, with the intention of using a 4S battery. I thought I had better get the flash image working correctly on the eval board before trying it on my custom board, however unfortunately I became stuck very quickly.
I have moved the jumper to JP3 (4S) then gone through the TPS25750 GUI selecting
- - EVM mode (top left)
- - 45W
- 60W
- Power Sink
- Host & Device
- USB 3.2 Gen 2
- No
- No
- BQ25790 or BQ25792
- 16.8V
- 1A (I have also tried 2A, 3A and other options)
- 0.08A (also tried 0.4A)
- 0.4A
I have built a file from this and flashed it no problem (using a third party CH341A flash tool). I have power cycled the EVM, disconnecting the battery and the USB cable, then waiting for the sys voltage to drop to 0.1V.
The problem I have is now when I connect a 4S battery (sitting at around 12.2V, i.e. moderately discharged), the charger does not start charging but instead the STAT light blinks at 1Hz. The datasheet for the BQ25792 says this is what happens in an error state, but no clue as to the error is given.
I have tried powering the USB socket first, then the battery (after flashing) and the other way round (battery then USB). It doesn't make a difference. The STAT light just flashes at 1Hz. Note the USB power in seems to be negotiating correctly and the voltage updates if I change the entry to question 3 on the GUI tool, so I don't think it's a flash image problem. I can see that updating the image updates the USB-PD negotation correctly. I think it is a problem with setting the parameters on the BQ25792. Any suggestions much appreciated.
Note I am using a real 4S battery not a dummy (4 Samsung 18650 cells in series) and a programmable load on the SYS output (currently turned off; it was just used to drain the battery so I could try to charge it).
Also note that before I flashed the device for the first time it worked correctly charging the battery drawing 17W from the USB so I don't think the hardware is faulty. I was hoping to get it fast charging at 2A but so far no joy.
Image of my setup:
I notice a similar query here but I have not managed to resolve my situation from it, unfortunately:
Please make suggestions as to what I could be doing wrong and if I need to change any of the "advance" settings in the GUI (not mentioned in any guides).
Thanks
Tony
