MP2672 - Power Path Management Question

I would like to use the MP2672 in a circuit similar to the example in the data sheet as follows:

I have a step-up converter off the battery that would draw as much as 9 amps off the 2 cell li-ion pack and I am curious if would be placed where the ‘motor driver’ is in the example and not cause damage to the charging chip if the USB power vin is active. Does the ‘optional FET’ in series protect the circuit as a result? Or am I off.

Hi willbond,

Welcome to the MPS Technical Forum. I will look into your questions and give an update soon. Thank you!

Hi willbond,

Theoretically, the 9A output could work because the charge current would be constant and the battery would supply the rest of the current. However, at some point the battery voltage would drop below charge voltage and the charger would stop. The input won’t be supplying all the power at max load and the battery will discharge. An over-discharged battery can fail in different ways so there needs to be protection there.

For the input FET, it’s there for overcurrent with a low input, such that if the SYS load is excessive or shorted, the input is turned off and the battery sees all the load. Also, if the input is invalid (i.e. too high) there is no exposure at the Vsw pin.

Bryan - makes sense thank you.