Lubomyr T. Romankiw

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An integrated voltage regulator (IVR) is presented that uses custom fabricated thin-film magnetic power inductors. The inductors are fabricated on a silicon interposer and integrated with a multi-phase buck converter IC by 2.5D chip stacking. Several inductor design variations have been fabricated and tested. The best performance has been achieved with a(More)
It is known that macromolecular organic matter in aquatic environments, i.e., humic substances, is highly aliphatic. These aliphatic macromolecules, predominantly paraffinic in structure, are prevalent in marine and lacustrine sediments and are believed to originate from algae or bacteria. A comparative study of mixed and pure cultures of green algae and(More)
Sensors capable of simultaneous measurement of pH and PO2 in an aqueous solution have been fabricated in planar form using microelectronic technology. Separate potentiometric metal-metal oxide pH and three electrode amperemetric PO2 sensors have been fabricated together on a silicon chip with active surface of 2 x 3 mm. Rhodium-rhodium oxide electrodes(More)
Energy consumption is a dominant constraint on the performance of modern microprocessors and systems-on-chip. Dynamic voltage and frequency scaling (DVFS) is a promising technique for performing “on-the-fly” energy-performance optimization in the presence of workload variability. Effective implementation of DVFS requires voltage regulators that can provide(More)
The use of lithography and electroplating to fabricate variable-reluctance, nearly planar, integrated minimotors with 6-mm-diameter rotors on silicon wafers is described. The motors consist of six electroplated Permalloy@ horseshoe-shaped cores that surround the rotor. Copper coils are formed around each core. The Permalloy and copper electroplating baths,(More)
The initial design of a vertical magnetoresistive head in a hand-held wand for reading magnetically encoded price tags and credit cards is discussed. The performance of the head (e.g., resolution, signal shape and amplitude, and signal-to-noise ratio) is analytically and experimentally evaluated as a function of the configuration of the sensor,(More)
The continuous and rapid increase of areal density in magnetic data storage systems required a continuous increase of the coercivity of the storage media. In order to be able to record on these everhigher-coercivity media, new soft magnetic materials for pole tips with increased magnetic moment had to be developed. Significant progress has been made during(More)
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