Fully-integrated switched-capacitor voltage regulator with on-chip current-sensing and workload optimization in 32nm SOI CMOS

Xiaoyang Mi, Debashis Mandal, Visvesh Sathe, Bertan Bakkologlu, Jae-sun Seo

Research output: Chapter in Book/Report/Conference proceedingConference contribution

3 Scopus citations

Abstract

Efficient, stable, and fast power delivery against fluctuating workloads have become a critical concern for applications from battery-powered devices to high-performance servers. With high density on-chip capacitors, fully-integrated switched-capacitor (SC) voltage converters provide high efficiency down-conversion from a battery or off-chip voltage regulation modules. However, maintaining such efficiency with minimal supply noise across a wide range of fluctuating load currents remains challenging. In this paper, we propose an on-chip current sensing technique to dynamically modulate both switching frequency and switch widths of SC voltage converters, enhancing fast transient response and higher efficiency across a wide range of load currents. In conjunction with SC converters, we employ a low-dropout regulator (LDO) driven by a push-pull operational transconductance amplifier (OTA), whose current is mirrored and sensed with minimal power and efficiency overhead. The sensed load current directly controls the frequency and width of SC converters through a voltage-controlled oscillator (VCO) and a time-to-digital converter, respectively. In 32nm SOI CMOS, the proposed voltage regulator maintains 77-82% efficiency at 0.95V output voltage with less than 20mV steady-state ripple across 10X load current range of 100mA-1A and 33mV droop voltage for a 80mA/ns load transition, while providing a projected current density of 6W/mm2.

Original languageEnglish (US)
Title of host publicationProceedings of the International Symposium on Low Power Electronics and Design, ISLPED 2015
PublisherInstitute of Electrical and Electronics Engineers Inc.
Pages140-145
Number of pages6
ISBN (Electronic)9781467380096
DOIs
StatePublished - Sep 21 2015
Event20th IEEE/ACM International Symposium on Low Power Electronics and Design, ISLPED 2015 - Rome, Italy
Duration: Jul 22 2015Jul 24 2015

Publication series

NameProceedings of the International Symposium on Low Power Electronics and Design
Volume2015-September
ISSN (Print)1533-4678

Other

Other20th IEEE/ACM International Symposium on Low Power Electronics and Design, ISLPED 2015
CountryItaly
CityRome
Period7/22/157/24/15

Keywords

  • low-dropout regulator
  • on-chip current sensing
  • switched-capacitor voltage converter
  • voltage-controlled oscillator

ASJC Scopus subject areas

  • Engineering(all)

Fingerprint Dive into the research topics of 'Fully-integrated switched-capacitor voltage regulator with on-chip current-sensing and workload optimization in 32nm SOI CMOS'. Together they form a unique fingerprint.

Cite this