One of the drawbacks of this circuit is that V(DRV) is still a function of the input voltage due to the R1, R2 divider.
In most cases protection circuits might be needed to prevent excessive voltage across the gate-to-source terminals.
Another potential difficulty is the saturation of the npn level shift transistor, which can extend the turn-off time otherwise
defined by R1 and R(GATE). Fortunately both of these shortcomings can be addressed by moving R2 between the emitter of Q(INV)
and GND. The resulting circuit provides constant gate driver amplitude and fast, symmetrical switching speed during turn-on and turn-off.