BQ40Z60: Under Current Protection

Leo Rodriguez

Part Number: BQ40Z60

Hi Battery Management Team,

Can you explain how the UCP works on the BQ40Z60? Specifically, how does it behave once the charging current is tapering down to termination.

I have an application with 4A of CC and a 600mA taper current. Evaluating my current design at input voltage corner cases, I may see ripple currents of 500mA - I want to check if UCP may cause the charger to stop prematurely in order to avoid negative current in the inductor.

Regards,

Leo

over 6 years ago

0 Batt over 6 years ago

TI__Mastermind 42535 points

Hi Leo,

There is no UCP in this device. The device average current needs to be lower than the taper current for 2 consecutive windows of 40s for charge taper to be detected.

0 Leo Rodriguez over 6 years ago in reply to Batt

TI__Intellectual 945 points

Hi,

I'm confused, there are several mentions of an UCP feature in the datasheet: Sections 7.36 and 9.2.2.1.

Leo

0 Batt over 6 years ago in reply to Leo Rodriguez

TI__Mastermind 42535 points

Ah, OK. I thought you were talking about fw. No, I don't think so in this case. The chg fet is controlled by the gauge and the acftet belongs to the charger, in either case if the fw doesn't detect taper it won't take action. As far as hw is concerned, it only matters if the gauge fw thinks the battery is fully charged.

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BQ40Z60: Under Current Protection