A 10-mW two-channel fully integrated system-on-chip for eddy-current position sensing [in biomedical devices]

Author

Oberle, Michael ; Reutemann, Robert ; Hertle, Jürgen ; Huang, Qiuting

Author_Institution

Integrated Syst. Lab., Swiss Fed. Inst. of Technol., Zurich, Switzerland

Volume

37

Issue

7

fYear

2002

fDate

7/1/2002 12:00:00 AM

Firstpage

916

Lastpage

925

Abstract

The use of magnetic bearings in small biomedical devices poses new challenges for the integration of complex embedded electronic systems. This paper describes a low-power fully integrated two-channel system-on-a-chip (SOC) for two-dimensional (2-D) differential position sensing in magnetic bearings through two pairs of eddy current sensors. It consists of a 312.5 kHz switched-capacitor (SC) sine-wave generator, a two-channel data acquisition unit including a 19-dB quadruple difference instrumentation amplifier, and a demodulating 12-bit ΣΔ analog-to-digital (A/D) converter with DSP-compatible serial interface. A signal-to-noise-plus-distortion ratio (SNDR) of more than 60 dB has been achieved, which corresponds to a resolution of better than 3 μm at a maximum displacement range of 3 mm. The entire system has been integrated in a standard 0.6-μm CMOS technology and consumes 10 mW at a 2.7-V supply

Keywords

CMOS integrated circuits; biomedical electronics; biomedical equipment; demodulation; eddy currents; instrumentation amplifiers; low-power electronics; magnetic bearings; magnetic sensors; mixed analogue-digital integrated circuits; position control; position measurement; prosthetics; sigma-delta modulation; switched capacitor networks; 10 mW; 2.7 V; 2D differential position sensing; CMOS technology; DSP-compatible serial interface; bandpass filter characteristic; blood pump; demodulating ADC; eddy-current position sensing; low-power system-on-chip; magnetic bearings; position control; quadruple difference instrumentation amplifier; small biomedical devices; switched-capacitor sine-wave generator; two-channel data acquisition unit; two-channel fully integrated system-on-chip; Biosensors; CMOS technology; Data acquisition; Eddy currents; Magnetic levitation; Magnetic sensors; Sensor phenomena and characterization; Sensor systems; System-on-a-chip; Two dimensional displays;

fLanguage

English

Journal_Title

Solid-State Circuits, IEEE Journal of

Publisher

ieee

ISSN

0018-9200

Type

jour

DOI

10.1109/JSSC.2002.1015691

Filename

1015691