BQ40Z50-R1: BQ50Z50-R1 Hardware Protection

Josue Malaver

Part Number: BQ40Z50-R1

Tool/software:

Hello, we were doing some testing on the fuel gauge IC, testing the hardware protection, and we're finding the results aren't matching the register settings.

We've currently set our to SCD2=0x23. This should be giving us a delay of 61us above 222A with the resistor value used for testing. But currently it seems like it takes a lot longer than that.

Also would appear that the FG waits for steady state on the current before applying the threshold, can you confirm if this is the expected behavior?

Green = Current.

5 months ago

0 Alan Frias 5 months ago

TI__Mastermind 25075 points

Hello Josue,

This question has been assigned and will be answered promptly.

Thank you,
Alan

0 Anthony 5 months ago in reply to Alan Frias

TI__Mastermind 28440 points

Hi Josue,

Can you please confirm the exact amount of time the delay is taking in the image above? Also, can you please confirm the AFE Protection Control [SCDDx2] bit is not set at this time?

Regards,

Anthony

0 Josue Malaver 5 months ago in reply to Anthony

Prodigy 10 points

SCDDx2 is not set.

The total pulse is closer to 400us as you can see. But part of the question is, does it count the entire width of the pulse? OR just when it reaches steady state? Even the steady state area seems to be >100us though.

0 Anthony 5 months ago in reply to Josue Malaver

TI__Mastermind 28440 points

Hi Josue,

There is another detection period that needs to be included for hardware protections. Please see the FAQ below discussing this:

https://e2e.ti.com/support/power-management-group/power-management/f/power-management-forum/1111094/faq-what-are-the-differences-between-the-hardware-and-firmware-protections

Regards,

Anthony

0 Josue Malaver 5 months ago in reply to Anthony

Prodigy 10 points

Hi Anthony,

Thanks for the link, this is useful. Do you have any comments on the steady state vs. transient behavior? Trying to understand if the device waits for the signal to stabilize before starting the counter.

0 Anthony 5 months ago in reply to Josue Malaver

TI__Mastermind 28440 points

Hi Josue,

I believe the counter should start immediately once the current has been observed by the AFE. It should not need to reach a steady state for an amount of time before the gauge observes it.

Regards,

Anthony

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BQ40Z50-R1: BQ50Z50-R1 Hardware Protection