I am somewhat confused by the sections of the BQ25798 datasheet pertaining to the input selection driven by ACDRV1/ACDRV2. In table 5-1, the pin description states that the charge pump will drive the voltage 5V above the common drain connection of the back-to-back N-channel MOSFETs. However, going by the drawings in figure 7-3 and figure 7-4, I would say that in fact the MOSFET sources share a common connection. Also, section 6.5 (electrical characteristics) does not seem to contain any information on ACDRV1/ACDRV2. Furthermore, would it be sufficient to connect the MOSFET gates directly to ACDRV1/ACDRV2 as indicated in figure 8-1? The EVM includes a 1nF capacitor in parallel to the Zener, as well as 294 Ohm resistor between the gates and the BQ25798 pin.
In my view, it would be helpful to explain this feature in somewhat more detail, and perhaps including some recommended components as part of a reference schematic.
Thanks!
