Aspects of the present invention are directed to techniques for improving the efficiency of power supply schemes by continuously and adaptively scaling voltage and frequency levels in an integrated circuit based on measured conditions in real-time, without resorting to a reliance on excessive pre-computed margins typical of conventional schemes. Embodiments of the present invention employ a self-tuning dynamic voltage control oscillator (or other similar clock signal generator) that sets the frequency for components in the integrated circuit. When a requested frequency exceeds a maximum allowed frequency for a given voltage level (accounting for other age and temperature related conditions), a look-up table is dynamically referenced to determine a new voltage level that is sufficient to safely and efficiently generate the requested frequency. The look-up table continuously receives updates on the operating conditions, and new voltage requests can be generated dynamically as necessary based on the system's current needs.

An oscillator includes: an oscillation circuit whose oscillation frequency changes based on a voltage that is applied to a variable capacitance element; and a voltage generation unit that generates the voltage which is applied to the variable capacitance element based on a control signal, in which the voltage that is generated by the voltage generation unit changes nonlinearly with respect to a change in the control signal such that a change in the oscillation frequency with respect to the change in the control signal is adjusted to come close to be linear.