Multiphase current controlled buck converter with energy recycling Output Impedance Correction Circuit (OICC): Adaptive Voltage Positioning (AVP) and Dynamic Voltage Scaling (DVS) application

Abstract

Modern microprocessors impose strict specifications on Voltage Regulating Modules (VRMs) with advanced features such as Dynamic Voltage Scaling (DVS) and Adaptive Voltage Positioning (AVP). In this study the Output Impedance Correction Circuit (OICC) concept is employed as an additional energy path in a Multiphase synchronous buck converter in a manner that, during the load steps transients, the output capacitor of 150 μF is virtually increased to 2.1 mF, thus improving the response under AVP operation. On the other hand, during the output voltage reference step, the OICC is inactive, facilitating DVS operation and reducing the current stress on the switches and the inductors. Furthermore, the proposed solution is compared with a reference converter with 2.1 mF output capacitor, for both AVP and DVS operations. The OICC is implemented as a Synchronous Buck Converter with Peak Current Mode Control (PCMC), having smaller penalty on the system efficiency comparing with Linear Regulator (LR) implementation.