A display device may include a display having a plurality of pixels. The display device may also include a replica pixel circuit having a switching device configured to output a first current based on a received voltage, a light-emitting diode (LED) configured to illuminate to a first gray level based on the first current output by the switching device, and current mirror circuitry configured to generate a second current that mirrors the first current. In addition, the replica pixel circuit may include a current source configured to output a reference current based on a voltage value that corresponds to the received voltage, comparator circuitry configured to determine a difference between the second current and the reference current, and voltage adjustment circuitry configured to adjust a source voltage output provided to the plurality of pixels based on the difference.