a method and apparatus for optimizing a light emitting diode operation range is provided . the method comprises the steps of : turning on at least one led ; and then measuring an anode voltage of the at least one led ; then measuring a cathode voltage of the at least one led . once the measurements are completed , a forward voltage of the at least one led is calculated . after the calculation , the at least one led is turned off and a power multiplexer switch threshold is set for that led based on the measured anode and cathode voltages .