In an example implementation, a level-shifter circuit in an integrated circuit (IC) includes a plurality field-effect transistors (FETs) coupled to provide: a first inverter having an input port configured to receive an input signal having a first supply voltage, an output port, and a bias port; a second inverter having an input port coupled to the output port of the first inverter, an output port, and a bias port coupled to a second supply voltage; a diode-connected FET coupled between the second supply voltage and the bias port of the first inverter; a first FET in parallel with the diode-connected FET having a gate coupled to the output of the second inverter; and a second FET in parallel with the diode-connected FET and the first FET having a gate configured to receive a mode select signal.