A system is provided for generating a plurality of different voltage level clock signals. The system comprises an electrical energy storage pack having a plurality of series coupled electrical energy storage cells that provide a plurality of different output voltage level, a reference oscillator that provides a reference clock signal and a plurality of voltage clamps that receive the plurality of different output voltage levels and output the plurality of different voltage level clock signals at respective output nodes. The plurality of voltage clamps are configured to clamp each of a given output node to a respective high-side voltage level in response to pulling up of the given output node toward a respective high output voltage level and to clamp each of the given output node to a respective low-side voltage level in response to pulling down of the output node toward a low output voltage level.