1. A circuit for generating a constant current, comprising: a first current generator that conducts a first current based upon a supply voltage and a resistive element and that generates a first mirrored current based on the current; a second current generator that generates a second current based on the first current wherein the second mirrored current decreases as the current increases and decreases as the current increases; and a summing circuit for summing currents proportional to said first and second currents to generate an output current.