Dissertation Talk: Power Management for Li-ion Battery to Processor Core Supply: A direct Power Delivery Scheme Enabled with a Hybrid DC-DC Converter Approach

Seminar | April 26 | 11 a.m.-12 p.m. | 531 Cory Hall

 Yongjun Li

 Electrical Engineering and Computer Sciences (EECS)

Due to limited platform size, most portable and wearable electronics call for a compact power management achitecture with high efficiency and high power density. The conventional buck converter requires bulky magnetics that consume a large amount of board areas. The switched capacitor (SC) converter, though promising for a fully integrated solution, is not efficient for continuous voltage regulation to cover a wide operation range. In this talk, we introduce a family of hybrid DC-DC converter topologies to mitigate the limitations in either purely inductive or capacitive power conversion approach.

The proposed hybrid topology enables efficacious use of standard CMOS technology as in a SC converter and at the same eliminate the fundamental charge sharing loss by leveraging much smaller inductance compared to buck converter. A intuitive model is developed to capture the operation principle and facilitate the control design. A silicon prototype was implemented in 0.15um CMOS process for achieving conversion > 3:1 with utilizing package interconnection loop as the effective inductor. The prototype achieves 87.2% peak efficiency with 83.4% at a power density of 0.46W/mm2 and 50mV undershoot/overshoot under a 0.4A on-die load step.

 CA, yongjunli@eecs.berkeley.edu, 510-517-7786