A driver circuit includes a first and a second voltage rail, a first pre-driver circuit, a power transistor, comparison circuitry which indicates when a voltage level of the first voltage rails is above or below a reference voltage level, a level shift circuit coupled between the first voltage rail and the second voltage rail which provides a level shifted output, a tapered buffer circuit coupled to the first voltage rail and to a first circuit node, wherein the tapered buffer circuit receives the level shifted output and provides a buffered output to a control electrode of the first pre-driver transistor, and a rail voltage adjusting circuit coupled between the first circuit node and the second voltage rail, which, in response to the comparison circuitry indicating that the voltage level of the first voltage rail is above the reference voltage level, adjusts a voltage level of the second voltage rail.