BQ40Z50-R3-DEVICE-FW: device supplied by power supply bugging

Clement MAGNIEN

Part Number: BQ40Z50-R3-DEVICE-FW

Hello,

I am using the BQ40Z50-R3. When I test the pcb with a power supply I have a bug (like in production after the golden file is loaded with the bqMtester, we need to test the pcb with a tester, there is no battery, only a power supply). If I use the ON/OFF switch of the PSU, bqstudio doesn't detect the BQ40Z50-R3(not communication), I need to short Vbatt+ and Vpack+ to activate the communication.

But if I plug manually Vbatt+ in the PSU, bq studio communicate with BQ40Z50-R3 and Vpack+ is activated.(don't need to short)

Any ideas? I suppose the rising time of the voltage is the problem.

Best regards,

Clementexport TI bug power supply.gg.csv

over 5 years ago

0 Kang Kang over 5 years ago

TI__Mastermind 24870 points

Hello Clement,

You will need to short it regardless. You should probe the PBI as well as the VCC and Pack pins to see what the differences are between these two methods.

0 Clement MAGNIEN over 5 years ago in reply to Kang Kang

Intellectual 390 points

Hi Kang,

The difference is the rising time, when a use the ON/OFF switch it's more than 50ms and the PBI is stuck at 0V.

Do you have information about the maximum rising time of Vbat? When the rising time is considered to be too long and trigger a fault?

Regards,

Clement

0 Kang Kang over 5 years ago in reply to Clement MAGNIEN

TI__Mastermind 24870 points

Hello Clement,

I don't think there is a specific rise time for Vbat. Can you plot both waveforms and show the working one where PBI is not stuck?

Power management

Power management forum

BQ40Z50-R3-DEVICE-FW: device supplied by power supply bugging