Title:  Fine-grain On-chip Power Management using Digital and Digitally-assisted Linear Voltage Regulators

Committee:

Dr. Arijit Raychowdhury, ECE, Chair , Advisor

Dr. Madhavan Swaminathan, ECE

Dr. Hua Wang, ECE

Dr. Maysam Ghovanloo, ECE

Dr. Paul Kohl, ChBE

Dr. Vivek De, Intel

Abstract:

Conventional power delivery using bulky off-chip voltage regulator module fails to adequately address the challenges posed on power delivery network by transistor and voltage scaling, increased parasitics, decreased decoupling capacitor budget, high power density and heterogeneity of load circuits. To address these challenges, this dissertation research demonstrates that digital and digitally-assisted linear voltage regulators serve as key design enablers for fine-grain power management right at the point of load inside a chip.

The proposed designs achieve both spatial and fast temporal adaptation of supply voltage needed to achieve unprecedented levels of performance and reduced energy consumption in big multi-core processors and system-on-chip platforms. They provide an opportunity for automated synthesis, desired process and voltage scalability thanks to their digital construction, wide operational dynamic range, low power overhead, and fast response times as compared to the state-of-the-art designs in linear voltage regulation. This dissertation research also provides theoretical models to understand operational dynamics of digital linear voltage regulators and builds a number of test-chips utilizing advanced control laws to enable voltage regulation of small digital functional units to large core sized digital circuits. Digital assisted hybrid linear voltage regulators build further on top of digital linear voltage regulators to enable fine-grain power management for all types of load circuits and not just digital load circuits achieving unprecedented levels of efficiency and performance. The designs covered in this thesis have significantly contributed towards understanding the operation and design of digital and digitally-assisted linear voltage regulators. These designs have helped in improving state-of-the-art in on-chip voltage regulation and enabled adoption of digital linear voltage regulators in commercial products.