Access MP2650 in battery only mode

Battery Management
1

Dear support team,

We are developing a system using MP2650, 2S battery and USB PD charging, system diagram as show below.

diagram
diagram1359×591 8.67 KB

In the system we have a low power MCU powered from MP2650 VCC pin. When system is powered by battery only and in off mode, we set MP2650 REG0Bh[1:0] to 00, disable PROCHOT and PSYS, also put MCU in sleep state.
If user click ON button, the MCU wakes up and subsequently turns on the main processor.
Our questions are:

  1. When MP2650 is in battery only and lowest power mode, can the MCU access I2C registers to turn on ADC and read battery voltage?
  2. When MP2650 is in battery only lowest power mode and MCU is sleep, when AC adapter is connected, will ACOK assert and can we use this to wake up the MCU?

TIA
Bob

2

Hi @baoshi.zhu,

  1. When the input is absent the, the Vcc LDO is powered by the battery. The I2C interface is ready for communication, and all registers are reset to their default values. The host can access all the registers. (refer the VCC LDO Output section)

  2. Yes, the AOCK is an open drain O/p pin indicating the presence of an adapter. You may need to configure the MCU to read this pin continuously. ( refer to ACOK indication and I2C interface)

Please let us know of you have any further question.

Thank you
Saurabh

3

Thanks Saurabh, the information is very helpful.
Just to confirm if both I2C and ACOK are working normally when REG0Bh[1:0] is 00 i.e. MP2650 is only consuming 40uA from battery.
Thank you
Baoshi