Title :
Ultra-Compact Power Conversion Based on a CMOS-Compatible Microfabricated Power Inductor with Minimized Core Losses
Author :
Galle, Preston ; Wu, Xiaosong ; Milner, Luke ; Kim, Seong-Hyok ; Johnson, Peter ; Smeys, Peter ; Hopper, Peter ; Hwang, Kyuwoon ; Allen, Mark G.
Author_Institution :
Georgia Inst. of Technol., Atlanta
fDate :
May 29 2007-June 1 2007
Abstract :
A CMOS-compatible microfabricated inductor is presented. The inductor consists of a planar spiral coil optionally sandwiched between upper and lower magnetic core layers. Core materials investigated include ferrite-filled polymer and electrodeposited nickel-iron permalloy (Ni0.80Fe0.20).Four core constructions were investigated: air-core (i.e., no magnetic material); lower permalloy core with upper air core; lower permalloy core with upper ferrite polymer core; and lower and upper permalloy core. In all cases with magnetic cores, a nominal magnetic air gap of 2 microns was utilized. As expected, the all-permalloy construction yielded the highest inductance. Inductors were characterized both by impedance analysis as well as in a prototype buck DC-DC conversion circuit. When the converter was operated at 5 MHz, peak efficiency of 82% and an efficiency of 80% at a load current of 2.5 A and output voltage of 2 V was obtained.
Keywords :
CMOS integrated circuits; DC-DC power convertors; iron alloys; magnetic cores; nickel alloys; power conversion; power inductors; CMOS-compatible inductor; NiFe; buck DC-DC conversion circuit; core materials; current 2.5 A; efficiency 80 percent; efficiency 82 percent; electrodeposited nickel-iron permalloy; ferrite filled polymer; frequency 5 MHz; magnetic core layers; microfabricated power inductor; minimized core losses; permalloy core; planar spiral coil; ultra-compact power conversion; voltage 2 V; Building materials; Coils; Core loss; Inductors; Iron; Magnetic cores; Magnetic materials; Polymers; Power conversion; Spirals;
Conference_Titel :
Electronic Components and Technology Conference, 2007. ECTC '07. Proceedings. 57th
Conference_Location :
Reno, NV
Print_ISBN :
1-4244-0985-3
Electronic_ISBN :
0569-5503
DOI :
10.1109/ECTC.2007.374056