I'm currently bulding and Android device and I've got a question which can't get answered.

The AXP209 is an IPS and power manager. It allow the usage and charge of a standard lipo.

It has two inputs : ACIN and USB VBUS. In a case of a tablet, will the IPS use VBUS to charge the battery and make the whole thing work, or is ACIN needed ?



Whatever; After some deeper search into the datasheet, I've found this :

The AXP209 power input can come from lithium battery (BAT),USB VBUS Input, external power supply (ACIN). The IPS will select an appropriate power source depending on the battery and external power conditions.

O When only the battery is available, no external power input, the battery powers the system;

O When there is a valid external power source(VBUS Or ACIN), is is the preferred power supply.

O When the external power is removed, the IPS will seamlessly switch over to battery power.

O When both VBUS and ACIN are available, ACIN will be used to power the system and recharge the lithium battery;

O If the ACIN cannot provide sufficient current, VBUS is also connected to source more current;

O If the drive capacity is still insufficient, then the charge current is reduced to zero, the battery is used to power the system

So in the case of the AXP209 IPS, the order is ACIN > VBUS > BAT. When one of it fails, by delivering not enough power or by simply being absent, the IPS chooses a better supply seamlessly.

The answer to the question is yes then, the IPS can be used without ACIN,

Edit : and yes I'm sorry not looking deep enough and answering my dump question by myself

  • 1
    \$\begingroup\$ Self answers are considered appropriate. They build up answers for anyone Googling the same problem. \$\endgroup\$ – user253751 Mar 5 '18 at 22:50

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