Systems and methods for generating reference voltages are provided. A representative system comprises a resistor circuit; a first switch coupled between a first end of the resistor circuit and a first power source; a second switch coupled between the first end of the resistor circuit and a second power source; a third switch coupled to a second end of the resistor circuit; a fourth switch coupled to the second end of the resistor circuit; a first resistor coupled between the first end of the resistor circuit and the first switch; a second resistor coupled between the first end of the resistor circuit and the second switch; a third resistor coupled between the second end of the resistor circuit and the third switch; a fourth resistor coupled between the second end of the resistor circuit and the fourth switch; and a control circuit for controlling the switches.