The disclosed technology provides circuitry for providing a DC output voltage. In accordance with one aspect of the invention, the circuit includes a power connection and a transistor connected to the power connection. A current source coupled to the transistor causes the transistor to pass at least a minimum current. The transistor's gate-to-source voltage can vary based on the current that passes through it, so that the minimum current established by the current source corresponds to a particular gate-to-source voltage. A reference voltage circuit is coupled to the transistor and causes a substantially constant voltage to appear on the gate connection of the transistor. The transistor's source connection carries an output voltage that is based on the gate voltage and the transistor's gate-to-source voltage. In accordance with one aspect of the invention, the DC output voltage circuitry has a substantially flat PSRR across frequencies of interest.