BQ40Z60: how to set max charging current and overcurrent in Charge Protection?

Bruce li

Part Number: BQ40Z60

Dear TI Expert,

My customer is designing a 3S pack with BQ40Z60, this is the first time they design gauge + charger solution, and they don't know how to set the OCC protection.

For example, if the charging current is set to 2A, and set OCC to 3A, does it make any sense since max charging is 2A and OCC never happen?

If it does make sense to prevent charger damage, then how to test OCC works? Re-set max charging current to above 3A or break the charger circuit and add a external high-current charger?

Or they just need to set OCC to equal to the max charging current? Thanks a lot.

over 7 years ago

0 Batt over 7 years ago

TI__Mastermind 42535 points

Hi,

Your thread's been assigned to me, please expect a reply within the next 2 days.

0 Batt over 7 years ago in reply to Batt

TI__Mastermind 42535 points

Hi Bruce,

OCC is essentially a protection for the BMU, not the charger. The charger will provide whatever current it is designed to provide that is requested by the BMU (if it's a smart charger). In case you want to protect the system from overcurrent in chg, please set OCC threshold to a nominal value (say 2200mA) if the charger provides 2A. That way if the current exceeds the safe threshold as determined by system designer, the BMU will open the FET and protect the system.

0 Bruce li over 7 years ago in reply to Batt

Genius 5580 points

Dear Batt,
Got it , thanks a lot for your help.

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BQ40Z60: how to set max charging current and overcurrent in Charge Protection?