BQ40Z80: 1W Radio Causing Current Readings

Jonathan Do

Part Number: BQ40Z80

Tool/software:

We are seeing issues where if our 2.4Ghz 1W radio antenna is placed too close to the battery, the BQ40Z80 will start believing there is current being passed through. This is causing issues where the battery will falsely detect a current through the pack and trip the CFETF or DFETF protection. We have observed this issue on our board designs and on the EVM. Are there any recommendations on how to mitigate this?

We have detected readings with the antenna up to 6 inches away.

6 months ago

0 Anthony 6 months ago

TI__Mastermind 28480 points

Hi Jonathan,

Jonathan Do said:
Are there any recommendations on how to mitigate this?

How much current is being observed at this time? Is it small enough to increase the CFETF and DFETF OFF Thresholds?

Regards,

Anthony

0 Jonathan Do 6 months ago in reply to Anthony

Prodigy 50 points

Unfortunately no, the readings we get can be over 1A. Sometimes up to 30A if the antenna is placed near enough

0 Anthony 6 months ago in reply to Jonathan Do

TI__Mastermind 28480 points

Hi Jonathan,

If the current is this large, this will need to be mitigated through the layout, whether that be through changing where the device is positioned or RF shielding implementations.

Regards,

Anthony

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BQ40Z80: 1W Radio Causing Current Readings