MP2651- VBATT to VBUS -Source Mode Operation

Battery Management
1

Hello,

I’m currently designing a 2S USB-C Power Bank using the MP2651 IC alongside the CCG3PA PD controller. This design, inspired by the MEZS7-1S-4SPDPowerbank, seems like the perfect choice for charging and discharging a power bank utilizing the USB PD 3.0 standard. In my design, I want to support Battery PDO as the source with Fixed PDOs (5V–20V) for both source and sink.

The questions are as follows:

  1. In source mode operation, how can I set the output voltage (VIN_SRC) to follow the battery pack voltage (VBATT)?

  2. Can I enable Q1 and Q3 to be always on so that current can flow from the battery pack (CFLR) to VBUS (IN)?
    image

  3. Or can I set the value of the Output Voltage Setting in the Source Mode register to be the same as the ADC result of the battery voltage?

2

Hello @ihot,

In source mode, the output can either be set via DAC or external FB pin. As long as the battery voltage is within the battery charge voltage regulation range(Vbatt_reg), the output voltage should follow the battery voltage.It is necessary for Q4 and Q3,switching at regular intervals(transitioning between buck, boost and buck-boost mode) while Q1 is always on.

Hope this helps.

Best,
Saquib