An efficient digital sliding controller for adaptive power-supply regulation

We propose a digital controller for adaptive power-supply regulation that uses sliding control, which is a widely used technique in switching power supplies for its fast transient response and robust stability. A novel reformulation of the sliding control law enables a simple and power-efficient digital implementation. The reference circuit can be either a delay line or a ring oscillator, and the sensor circuits for both cases are discussed. The prototype chip fabricated in 0.25-mum CMOS technology demonstrates a power efficiency of 89%-95% over the regulated voltage range of 1.1-2.3 V.