BQ25611D: Part failing during normal operation. Cannot isolate cause.

Ryan Walker

Part Number: BQ25611D

Hello,

I am working on a new design with the BQ25611D but the part keeps failing at seemly random times to the point where the part appears to be physically damaged. After the failure we cannot talk to the part, it does not provide VSYS, and is warm to the touch. Obviously something is causing a major failure of the part, but we have isolated the part and are using the provided reference design.

I'm hoping something obvious might jump out at an expert here, or provide some insight into what could cause this type of failure. I have attached portion of our schematic for reference.

Before the failure everything appears to be operating as expected, and the contents of the 3 status registers are provided below. With nothing happening, the device will suddenly reboot, then fail completely.

Charger Status 0 Register (0x08):
1010 0101

Charger Status 1 Register (0x09):
1000 0101

Charger Status 2 Register (0x0A):
1100 0000

With the failure happening seeming randomly, we've had a hard time narrowing down the cause of failure. Any advice would be appreciated.

Thanks,
Ryan

over 3 years ago

0 Ning T over 3 years ago

TI__Guru 58001 points

Ryan,

1. Please visit https://e2e.ti.com/support/power-management-group/power-management/f/power-management-forum/993268/bq25611d-bq25611d-schematic-review/ for BQ2561X: Schematic Review and PCB Layout Design Tips

2. Are the register readings right before or after the issue? Could you please provide all the register readings before and after the issue?

Thanks,

Ning.

0 Ryan Walker over 3 years ago in reply to Ning T

Prodigy 65 points

Hi Ning,

1. Yes, I have been through the entire forum for the BQ25611D and came across this document already. Yes, we have checked everything as described in that document.

2. These would be the registers before the part fails. We cannot access the registers afterwards because the chip appears to be irreparably damaged.

It is a little concerning that that part appears to be physically failing, and then afterwards goes on a thermal runaway and becomes dangerously hot. Could it be related to something downstream of the device?

Thanks,

Ryan

0 Ning T over 3 years ago in reply to Ryan Walker

TI__Guru 58001 points

Ryan,

Did you try to shut down the charger completely (i.e. remove both the battery and the VBUS input), then power up again, does the part recover to work?

Thanks,

Ning.

0 Ryan Walker over 3 years ago in reply to Ning T

Prodigy 65 points

Hi Ning,

Yes, we have tried this. The part appears to be physically damaged. I can no longer talk to the part. Are there any measurements I can take to help determine the state the chip is in?

Thanks,
Ryan

0 Ning T over 3 years ago in reply to Ryan Walker

TI__Guru 58001 points

Ryan,

After completely shutdown, please connect a 4V lab power supply at the BAT pin. Is there output voltage at the SYS pin and are you able to communicate via I2C?

Thanks,

Ning.

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BQ25611D: Part failing during normal operation. Cannot isolate cause.