A system and method (400) for producing a reference signal is provided. The method includes supplying (405) a first current to a diode, sampling (410) a first voltage across the diode, supplying (405) a second current to the diode, sampling (410) a second voltage across the diode, converting (415) the first voltage and the second voltage to a first digital value and a second digital value, and determining (420) a digital reference value from the first digital value and the second digital value. The first voltage is based on the first current, and the second voltage is based on the second current.