So I was looking through the MAX713 datasheet and came across the schematic below. In short, MAX713 is a NiCd battery charging IC and below is shown the schematic for it in the the switching mode. The DRV pin is a 30mA current sink PWM output. Sinking the current turns the PNP Q1 on and the NPN Q2 transistor off, thus pulling the P-channel M1 transistor gate to the power and turning it off, so in a way it inverses the output.
I have two questions about this schematic.
1) Why is the Q1-Q2 pair needed after all? Won't just the R2 resistor be enough?
2) Can the Q1 and Q2 be just switched places to put a much more common N-Channel MOSFET instead of the P-Channel M1?
3) Is there any reason to use a P-Channel MOSFET here after all?