BQ33100: "VB_T2H_NACK" in BQ Evaluation Software when BQ33100 is connected

Venkat Ramaiah Vemula

Part Number: BQ33100
Other Parts Discussed in Thread: BQ24640, , EV2400

Tool/software:

Hi,

I'm using BQ33100 for capacitor stack (5Nos) monitoring, and the charger IC is BQ24640.

We included a P-FET for pack charging control, but the BQ33100 is not turning on the P-FET even though sufficient power is available to the board. I tried checking the registers through a terminal (BQ33100 i2c is connected to Toradex iMX8 SOM) for any faults, but no faults were observed.

I found a similar issue in this TI forum thread, which suggested a file update might be necessary(https://e2e.ti.com/support/power-management-group/power-management/f/power-management-forum/1006869/bq33100-p-fet-is-not-turning-on-when-power-is-availble)

For that, I connected the board to EV2400. Initially, I connected only SDA and SCL, which resulted in no device detection. Later, I connected the board ground (GND) to VSS of EV2400, and then the device was detected, but a "VB_T2H_NACK" error occurred. How can I overcome this error?

7 months ago

0 Diego 7 months ago

TI__Mastermind 25915 points

Hi,

Your device should auto detect by EVSW.

Are you using an EVM?

Did you download the FW package for the BQ33100?

Regards,

Diego

0 Venkat Ramaiah Vemula 7 months ago in reply to Diego

Prodigy 10 points

Hi,

Are you using an EVM?

--- Yes, I'm using EV2400

Did you download the FW package for the BQ33100?

--- No.

I just wanted to read the registers from BQ33100 using this EV2400.

Venkat

0 Diego 7 months ago in reply to Venkat Ramaiah Vemula

TI__Mastermind 25915 points

Hi,

I am asking if you are using the BQ33100EVM, the red PCB board, designed by TI.

You will need to download the FW package from the BQ33100 product folder. BQ33100 data sheet, product information and support | TI.com

Regards,

Diego

0 Venkat Ramaiah Vemula 7 months ago in reply to Diego

Prodigy 10 points

Hi,

I am not using the BQ33100EVM, instead, the BQ33100 IC is integrated into our custom-designed carrier board.

Currently, the IC is being detected in the BQEvaluation software, and I am able to read parameters like capacitance, voltage, etc., as well as the registers also.

However, my concern is that the IC is not turning on the PFET to charge the capacitors, even though there are no errors in the registers.

If I manually turn on the PFET, the FC flag status changes, but the IC does not turn off the PFET.

Regards

Venkat

0 Diego 7 months ago in reply to Venkat Ramaiah Vemula

TI__Mastermind 25915 points

Hi Venkat,

Are there any protection events happening?

Regards,

Diego

0 Venkat Ramaiah Vemula 7 months ago in reply to Diego

Prodigy 10 points

Hi,

Are there any protection events occurring? — No.

Whenever I turn on the FET, the CHG bit in the FET control register (0x46) changes.

The FC bit changes from 0 to 1 after a while (once the capacitors are fully charged) in the operation status.

0 Diego 7 months ago in reply to Venkat Ramaiah Vemula

TI__Mastermind 25915 points

Hi,

Can you share a schematic.

Regards,

Diego

0 Venkat Ramaiah Vemula 7 months ago in reply to Diego

Prodigy 10 points

Hi,

We are following the below sequence for our process. Please review and suggest if I’m missing anything or doing something incorrectly:

IC assembly on the board.
Connecting the evaluation board to the custom board.
Powering ON the board.
Detecting the BQ33100 in the evaluation module.
Ensuring that both the Safety Status register and the Operation Status show all green.

Test 1 (Manually Turn ON FET):

After manually turning ON the FET, the capacitors charge up to 10.5V, but the nominal voltage shown in the BQ33100 is only 9V.
The CHG FET in the Operation Status register is not turning off automatically.

Test 2 (Giving 0x0021 to Manufacturer Access 0x00):

When the new board is powered ON and the BQ33100 is detected, I send 0x0021 to 0x00.
After sending the command, the LTE and CFET statuses in the Operation Status register change.
The capacitors charge up to 10.5V, but again, the CFET does not turn off automatically.
Occasionally, the CB and DSG bits toggle between 0 and 1.

Regarding the CFET automatic turn ON/OFF behavior (to ensure no hardware issue):

I sent 0x0021 followed by 0x0025 (Learn Initialization) as a test.