TIDA-050047: Battery charger configured by TPS25750 to single cell !?

Hello,

I'm struggling with the evaluation of the TPS25750/BQ25792 combo using USB-PD-CHG-EVM-01.
I'm simply trying to get a 3S battery charged using an USB-PD adapter, and cannot get it working.

Here is what I've done:

I've used the TPS25750_Application_Customization_Tool 7.0.2 to generate a full-flash binary saved as a C file. I used the same settings as described in the TIDA-050047 manual, except for the charge current which I limited to 2.6A. As I don't have an Aardvark programmer, I made a simple firmware to program the EEPROM, with a re-read to ensure everything has been written correctly. I then reset the board by removing the battery and plugging it back in after making sure the battery selector was on JP2 (3S). After I connected the USB-PD the PD negotiation seems to work well (20V on PPHV test point) but the charger the STAT led blinks at 1Hz, indicating a fault...

So I tried to investigate my problem, wrote some code to get the charger status, and here is what I found out:

• After a reset, the charger seems to be configured correctly
  
minimal_system_voltage: 9000 mV
charge_voltage_limit: 12600 mV
charge_current_limit: 2600 mA
input_voltage_limit: 3600 mV
input_current_limit: 3000 mA
precharge_control: 0x0A
> Battery threshold precharge to fast charge: 15% VREG
> Precharge current limit: 400 mA
termination_control: 0x0A
> REG_RST: Not reset
> Termination current: 400 mA
re_charge_control_register: 0xA3
> Battery cell count: 3
charger_control_1: 0x80
charger_control_2: 0x00
charger_control_5: 0x1C

• When I connect the USB-PD charger, the TPS25750 sends some configuration to the charger
  
  >write to 0x6B ack data: 0x16 0xC0
>write to 0x6B ack data: 0x03 0x01 0x04
>write to 0x6B ack data: 0x01 0x04 0xEC
>write to 0x6B ack data: 0x0A 0x00 0x00
>write to 0x6B ack data: 0x16 0xC0
>write to 0x6B ack data: 0x0A 0x00 0x00"
  
  
• If I read back the configuration of the charger, it is setup as single cell, and the reported fault is "VBAT over-voltage status: Device in over voltage protection"
  
  minimal_system_voltage: 3500 mV
charge_voltage_limit: 4200 mV
charge_current_limit: 2000 mA
input_voltage_limit: 3600 mV
input_current_limit: 3000 mA
precharge_control: 0x0A
> Battery threshold precharge to fast charge: 15% VREG
> Precharge current limit: 400 mA
termination_control: 0x0A
> REG_RST: Not reset
> Termination current: 400 mA
re_charge_control_register: 0x00
> Battery cell count: 1
charger_control_1: 0x80
charger_control_2: 0x00
charger_control_5: 0x1C
VBAT over-voltage status: Device in over voltage protection
  
  

Here is the export from the configuration program: {"questionnaire":{"version":"7.0.2.2","answers":[0,2,3,1,3,3,1,null,1,null,0,12.6,2.6,0.4,0.4],"options":{},"configID":"0000","vendorID":"0000"}}

Any idea on what's wrong ?

Best regards,

Patrick