Abstract: A system includes a switching transistor that provides a current source to a load when activated by an input voltage and at least one Zener diode connected in parallel with the load that acts as a shunt regulator. The system may be especially suited for matching the controlled luminance of light emitting diodes to the controlled luminance of incandescent lighting. The system may also be useful for displays where a single master voltage regulator switch or controller controls the different types of lighting. The system may be packaged in a chip scale package for compactness, reduced weight, cost effectiveness, and higher efficiency and reliability.