To improve noise rejection, a native (or undoped) NMOS transistor is used as a source follower in place of a conventional common source PMOS transistor in a voltage regulator circuit. The native transistor has a threshold voltage of approximately 0 volts which allows the maximum voltage output of the regulator to be higher by one threshold voltage of a conventional NMOS transistor than might be obtained from a voltage regulator that used a conventional NMOS transistor. Alternatively, a depletion transistor can be used to provide even higher output. In another illustrative embodiment, a conventional bandgap reference circuit is modified by replacing a common source transistor connected to the output of an op amp with a native MOS transistor connected as a source follower.