BQ21080: input current

Hi,

IIN Consumption is minimal when the VIN is at sleep voltage or below. Sleep voltage is achieved when the input voltage is not high enough to charge the battery, this means that they can achieve lower IIN consumption, but they will not be able to charge in this state, it may be best to have IIN disconnected altogether at that point.

Can you share why the emphasis on the low IIN consumption? Is this connected to another battery?

Best Regards,

Juan Ospina

Hi Juan,

Thank you very much for your suggestion.

His target application is TWS earbuds. Either BQ21080 or BQ25180 is planned to place on the earbuds side and supplied the power by a battery placed on charging box or cradle.

I understnad sleep input current ISLEEP_IN is the lowest IIN when input power is attached.

Since this customer is looking for less than 20uA sleep current liniear charger, would you let us know any other product to meet his requirement.

I suppose that once ebardbuds is fully charged with cradle attached BQ21080 IIN consume from the battery on cradle side and he would like to minimize IIN in such case. However I am thinking killing the cradle supply current by DCDC converter or load switch makes resolve this case. Could you happen to know how other TWS manufactureres take care this current ?

Best regards,
 

Hi Toshiro,

I believe in typical applications the DCDC converter (typically a boost or buck-boost) is disabled in the cradle while the device is not actively charging. Since the headphones aren't in use and are in a low-power state while in the charging case typically, though a load switch would also help to minimize the quiescent current consumption.

In terms of parts, one alternative to consider is BQ2407x parts which seem to have lower IIN current if the workaround alternatives, though it doesn't have a low quiescent current ship-mode state.

Best Regards,

Juan Ospina