In examples, apparatus and methods are provided that mitigate buffer slew rate variations due to variations in output capacitive loading, a fabrication process, a voltage, and/or a temperature (PVT). An exemplary embodiment includes an inverting buffer having an input and an output, as well as an active resistance series-coupled with a capacitor between the input and the output. The resistance of the active resistance varies based on a variation in a fabrication process, a voltage, and/or temperature. The active resistance can be a passgate. In another example, a CMOS inverter's output is coupled to the input of the inverting buffer, and two series-coupled inverting buffers are coupled between the input of the CMOS inverter and the output of the inverting buffer.