The dual-gate W-switched power MOSFET: a new concept for improving light load efficiency in DC/DC converters

Author

Williams, Richard K. ; Grabowski, Wayne ; Cowell, Andrew ; Darwish, Mohamed ; Berwick, Jeff

Author_Institution

Siliconix Inc., Santa Clara, CA, USA

fYear

1997

fDate

26-29 May 1997

Firstpage

193

Lastpage

196

Abstract

A merged dual-gate power MOSFET is described which greatly improves the light-load energy efficiency of high-speed (f>1 MHz) low-voltage DC/DC conversion by dynamically reducing input capacitance and gate drive losses during low-current load conditions. The W-switched MOSFET concept is experimentally verified using a TrenchFET employing a 30× reduction in input capacitance during light load. Efficiency improvements better than 25% and a decade increase in useable load current were confirmed for a 1-cell Li ion to 5 V boost converter, without adversely affecting the converter´s transient response. Various figure-of-merits for W-switched MOSFETs are also proposed to analyze the limits of W-switching

Keywords

DC-DC power convertors; MOS integrated circuits; capacitance; field effect transistor switches; power MOSFET; power field effect transistors; power integrated circuits; power semiconductor switches; 1 MHz; 5 V; DC/DC converters; TrenchFET; dual-gate W-switched power MOSFET; gate drive losses; high-speed conversion; input capacitance; light load efficiency improvement; low-voltage conversion; transient response; Batteries; Capacitance; DC-DC power converters; Energy efficiency; Feedback; MOSFET circuits; Power MOSFET; Switches; Transient response; Voltage;

fLanguage

English

Publisher

ieee

Conference_Titel

Power Semiconductor Devices and IC's, 1997. ISPSD '97., 1997 IEEE International Symposium on

Conference_Location

Weimar

ISSN

1063-6854

Print_ISBN

0-7803-3993-2

Type

conf

DOI

10.1109/ISPSD.1997.601468

Filename

601468