A low power switching power supply for self-clocked systems

This paper presents a digital power supply controller for variable frequency and voltage circuits. By using a ring oscillator as a method of predicting circuit performance, the regulated voltage is set to the minimum required to operate at a reference frequency which maximizes energy efficiency. Our initial test silicon, implemented with a fixed frequency controller is analyzed and reveals that the controller´s power consumption is a major limitation for such a design. To make the controller power dissipation scale with the CV²f power of the load, we introduce a new architecture with variable frequency control, which allows the controller´s supply and frequency to scale along with the load device