BQ40Z60: .gg Golden Settings File changing after being sealed

James Rr

Part Number: BQ40Z60
Other Parts Discussed in Thread: BQSTUDIO

Hello,

i am using a BQ40Z60 battery management chip in a custom circuit board to manage a 4S LiPo battery. A golden image .gg settings file has been made, and the settings perform well as configured.

However, after the device is sealed and sent to other users of the device, the settings change (not only the RA Table values and QMax values, but also the Protections Threshold settings and other main settings that change the behavior of the system.) My understanding is sealing the device should prevent these settings from changing until the device is again unsealed in Battery Management Studio.

Also, I have tried to change the Update Status setting to value "02" as mentioned in this post (https://e2e.ti.com/support/power_management/battery_management/f/180/t/427788),

over 7 years ago

0 Damian Lewis over 7 years ago

TI__Mastermind 34775 points

Hi James,

How did you verify that your gauge was sealed before shipping?

www.ti.com/.../sluua04d.pdf

Page 106 & 107 table 11-1 lists the functions that are available in sealed mode

Page 120 Table 11-2 explains the state of the security bits in OperationStatus() register for sealed and unsealed modes.

It's not possible to modify some of the parameters you listed above like protection thresholds.

Can you provide us with details of your sealing processes and verification?

0 James Rr over 7 years ago in reply to Damian Lewis

Prodigy 120 points

Yes, the system is setup to automatically seal the chip upon pulling the system present pin low to begin operation. This seal code then remains in place until the user manually unseals the chip in BQ Studio.

0 Damian Lewis over 7 years ago in reply to James Rr

TI__Mastermind 34775 points

So i'm assuming you verified that the gauge was sealed using bqStudio after pulling system present pin low on all the gauges before sending to other users, right? Did you verify the golden image dataflash settings as well?

0 James Rr over 7 years ago in reply to Damian Lewis

Prodigy 120 points

Correct, the chip was verified as sealed in bqStudio (SEC1 and SEC0 were enabled).

Yes, the golden image settings were verified by Write All, and then Read All to verify the file was written to the chip.

Is there any other way the settings can change during normal operation cycles of charge and discharge of the battery?

0 Damian Lewis over 7 years ago in reply to James Rr

TI__Mastermind 34775 points

The parameters you mentioned previously should be updating in normal operation and can only be updated if the gauge is unsealed. Can you send us a gg file comparison of the parameters that were updated, so we can provide more details on the ones that shouldn't be updated in sealed mode.

0 James Rr over 7 years ago in reply to Damian Lewis

Prodigy 120 points

This file shows the changed settings:

This file shows the golden image settings:

Power management

Power management forum

BQ40Z60: .gg Golden Settings File changing after being sealed