What happens if we use low-side MOSFET driving in the BMS? Many Chinese AFE ICs drive the MOSFETs from the negative side — if we apply the same technique to this MP2797 AFE, what effects should we expect?
Apologies for the delay on this request.
I can only assume that you are referring to the FETs connected to CHG and DSG:
I would stick to the typical application of the MP2797 where the charge and discharge FETs are oriented regularly.
While this hasn’t been tested, the high-side FETs referenced to PACK+ is the focus of the design as opposed to the low-side referenced to PACK- (which could warrant FETs driven from the negative side).
In short, doing this with the MP2797 would surely introduce functional and safety issues.
Low-side FETs would only make sense when the AFE explicitly supports this and if the current sense / gate drivers are designed around some fixed ground reference. VMID should be between two high-side FETs.