Fully Time-Based PID Controller for a High Frequency Buck Converter

With the shrinkage of process nodes for integrated circuits, analog circuits, like analog feedback control, have become increasingly expensive and more challenging to design. Here timebased control is a compelling alternative to traditional analog feedback control circuits due to its better scaling with the process node. Several publications about time-based PID-type controllers exist. There the PI-part is implemented in the time domain, but the D-part remains in the analog domain thereby limiting the process scaling benefits. This paper proposes a new PID structure that fully integrates the PID in the time domain. The proposed structure has improved ripple attenuation and maps directly to a typical PID. Simulations shows that the performance of the theoretical small signal controller translates well to the large signal time-based response