AXP209 datasheet(15/45 Pages) ETC2

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AXP209

Enhanced single Cell Li-Battery and Power System Management IC

9. Control and Operation

When AXP209 powers on and TWS interface SCK / SDA pins are pulled to host IO voltage source, the host

can then adjust and monitor the AXP209. This provides f

lexible adjustment and monitoring options, and a

wealth of information.

Note: "Host" Referring to the main application processor

Note: "External power supply" refers to ACIN And VBUS Inputs.

9.1 Power On / Off & Reset

Button(PEK)

AXP209 PWRON Pin can be connected to GND through a button, as a Power Enable Key (PEK) o

hibernation/wake button. The AXP209 can automatically identify long and short button presses and

react accordingly.

Power on Sources:

1. ACIN, VBUS, and battery

2. N_OE transition from high to low.

3. PEK press

Power On

System power-on is initiated whenever the following conditions occur:

1. When N_OE is low, and upon connection of a power supply that meets the requirements

(ACIN Or VBUS > 3.8V, and the battery voltage is higher than the shutdown voltage), AXP209

will automatically boot (Automatic booting on power supply connection can be configured by

the developer).

2. N_OE is low and the system is powered off, press PEK can power on AXP209. If required the

Host

3. When there is a valid external power source or battery present and N_OE changes from high to

low, AXP209 will be turned on.

After power on, DC-DC and LDO will be soft booted in a preset timing sequence, and then either the

Host or PWREN the pin can enable/disable power.

Shutdown (Power off)

When you push-and-hold PEK longer than IRQLEVEL, HOST can write “1” into“REG32H [7]” to inform

AXP202 to shutdown, which can disable all power output except LDO1.

System power-off is initiated whenever the following conditions occur:

1. Input voltage is too low( Low-Power Protection)

2. Power output voltage is too low due to overload( Overload Protection)

Confidential

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