What is SEALED mode in bq78350 gas guage

KESHUN LU

Prodigy 50 points

Other Parts Discussed in Thread: BQ78350, BQSTUDIO

As title stated, what is a SEALED MODE exactly? it doesn't explain the term in datasheet at all.

I need some advises. Thanks a lot

over 10 years ago

0 Jason Gin over 10 years ago

Genius 3970 points

Hi Keshun,

The SEALED security state in TI gauges locks the device's Data Flash memory, preventing anyone who does not have the Unseal Key from accessing the memory contents. For SBS (Smart Battery System) gauges, it also disables extended SBS commands, and only allows the official commands in the SBS specification to be used. Battery packs that use fuel gauges will almost always be shipped in the SEALED state.

See SLUUAN7A (the bq78350 technical reference manual), page 67 for more information about the different security states in the device.

If you have any more questions, feel free to ask!

Jason

0 ThomasCosby over 10 years ago

TI__Guru 73830 points

Sealing the device limits access to reading and modifying the flash memory and from reading a lot of the SMBus commands. The commands defined by the SBS standard are still available. This mode is a protection feature to to restrict access to the device.

0 KESHUN LU over 10 years ago in reply to Jason Gin

Prodigy 50 points

Many appreciation Jason. So if I used "FET-EN" command from bqstudio to turn on the mosfet, and I sealed the device, do I still have the mosfet turning on after I do a power cycle( unplug and plug the battery)?

0 KESHUN LU over 10 years ago in reply to ThomasCosby

Prodigy 50 points

Does the seal feature also "locks" the Data Memory after I modified them in bqstudio?

0 ThomasCosby over 10 years ago in reply to KESHUN LU

TI__Guru 73830 points

It locks user access to change the DF. The gauge can still change it as needed.

0 KESHUN LU over 10 years ago in reply to ThomasCosby

Prodigy 50 points

Thanks a lot Thomas.

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What is SEALED mode in bq78350 gas guage