Abstract: A system supplies power to and controls the frequency of electronic circuitry. The system comprises a DC source for supplying power to the electronic circuitry and a voltage controlled oscillator powered by the DC source. An output of the oscillator provides a system clock for the electronic circuitry such that as a voltage of the DC source continuously drops, the operating voltage of the electronic circuitry and oscillator continuously drops and the frequency of the system clock continuously drops in a manner corresponding to the continuous drop in operating voltage. Thus, the oscillator supplies an operating frequency tailored to the operating voltage to permit the electronic circuitry to operate at high speed.