An electrical current (“I”) digital-to-analog converter (“IDAC”) (60) supplies a specified electrical current to at least one light emitting diode. The IDAC (60) includes a plurality of current sources/sinks (26): a. that are connected in parallel so a total amount of current flowing through the at least one LED equals the sum of their individual electrical currents; and b. at any instant in time individual current sources/sinks (26) are either: 1. turned on: or 2. turned off. When the specified electrical current being supplied exceeds a pre-established threshold (94), a sequence of individual current sources/sinks (26) are turned on ever more quickly to produce a. non-linearly increasing electrical current. When the specified electrical current being supplied is below the pre-established current threshold (94), the non-linearly increasing electrical current is supplied by an increasing number of additional current sources/sinks (26), each additional current source/sink (26) producing progressively longer current pulses until that current source/sink {26} remains fully on.