Abstract
This work presents a fully integrated hybrid inductive/capacitive converter maintaining high efficiency for a load range of 2 mA to 140 mA (70×) suitable for the dynamic voltage scaling (DVS) based loads. This high efficiency is achieved by using an inductive converter for higher loads (15–140 mA, 0.50–0.9 V) and a capacitive converter for lighter loads (2–5 mA, 0.40–0.55 V) with a 50 mV hysteresis margin. A digital state machine activates the appropriate converter based on the power efficiency and enables the converter hand-over. The functional feasibility of implementing digital circuits as representative loads under the inductor is shown thereby increasing the peak converter power density from 0.387 W/mm2 to 4.1 W/mm2 with only a minor hit on the efficiency. The maximum measured efficiency is achieved in inductive mode of operation and decreases from 76.4% to 71% when digital circuits are present under the inductor. The design was fabricated in IBM’s 32 nm SOI technology.
Highlights
The demand for smaller form factors coupled with longer battery operation places stringent requirements on the power dissipation of integrated circuits in battery powered devices
The power savings achieved in a Dynamic voltage frequency scaling (DVFS) based system becomes evident when we observe the that the power has a cubic dependence on the supply voltage [3] as shown in Equation (1)
We propose to reuse the area under the inductor for digital loads as only the top two metal layers are used for the inductor
Summary
The demand for smaller form factors coupled with longer battery operation places stringent requirements on the power dissipation of integrated circuits in battery powered devices. Due to the comparatively slower improvement in the ampere-hour capacity of batteries, there is increased pressure on circuit designers to achieve greater battery life from existing battery technology. Device scaling reduces the parasitic capacitance being switched and reduces dynamic power dissipation. Dynamic voltage frequency scaling (DVFS) is one of the most widely used techniques to reduce power dissipation in digital circuits [2]. The power savings achieved in a DVFS based system becomes evident when we observe the that the power has a cubic dependence on the supply voltage [3] as shown in Equation (1)
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
