BQ21040: Charger FAN solution

James Zhan

Part Number: BQ21040
Other Parts Discussed in Thread: TPS60150

Hi team,

My customer is developing a charger FAN project with single-cell Li-Ion (4.2V) battery. Now they want have a white LED to drive, which require a 4V/50mA input.

They concern if they hook the LED on the battery side, when the battery is down below 4V, the LED don't work, so it may need a boost converter which will have higher cost and space.

Or could we just use a switching node charger's OTG function to drive the LED. But there is one concern, if the charger is always OTG mode, when plugging in the adapter, how this OTG shut down and start charing? And they don't want to have the LED disabled during this time.

Do you have the recommendation for this application?

They want the charger to be low power consumption, charging current 1A, and no BGA package.

Thanks for you help.

over 6 years ago

0 Bill Johns over 6 years ago

TI__Guru 69771 points

Could the customer possibly use a capacities charge pump to increase the battery voltage to power the white LED. The TPS60150 is a 2 X 2 SON package with low Iq current.

0 James Zhan over 6 years ago in reply to Bill Johns

TI__Expert 4365 points

Hi Bill,

I've recommended the TPS60150 to the customer, but they want to add another MOS to turn off the power rail of TPS60150 because the Iq is too big for them.

Actually, they want a very low power consumption solution for this end equipment, because they want the end user charge the FAN every three or four month.

Do you have a better solution for this? Thanks.

James

0 ezhao over 6 years ago in reply to James Zhan

TI__Genius 10240 points

James,

Bill recommended the best available solution.

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BQ21040: Charger FAN solution