Front-end ASIC for Spaceborne Fluxgate-Magnetometers

Mario Auer, Maximilian Scherzer, Aris Valavanoglou, Stefan Leitner, Werner Magnes

Publikation: KonferenzbeitragPoster


For the design of the next generation fluxgate-magnetometers for space applications an ASIC is currently being developed in cooperation between the Space Research Institute (Austrian Academy of Sciences) and the Institute of Electronics (TU-Graz). The ASIC contains the analog read-out electronics of the measurement system.
Commonly, a single-axis fluxgate sensor for space application is made of a soft magnetic ring-core placed in the center of a solenoid pickup coil. The ring-core is toroidally wrapped with a homogenous single layer of drive windings (also excitation coil). With the excitation coil the soft magnetic material is periodically saturated at a fundamental frequency of several kHz (F0) by feeding an AC current through the drive windings. The output signal of the pickup coil contains odd and even harmonics of the fundamental drive frequency. The even harmonics are proportional to the external magnetic field along the magnetic axis of the sensor. The odd harmonics constitute the feed-through signal coupled from the drive coil and the soft magnetic core to the pickup coil. The readout electronics has to perform the extraction of the magnetic field information by converting the even harmonics (or just the second harmonic) into a DC or slowly changing AC output voltage according to the bandwidth of the magnetometer. Using an additional feedback coil, a feedback loop is created that compensates the ambient magnetic field hereby extending the linearity and measurement range of the magnetometer.
While the final design will contain four channels, three magnetometer read-out channels and one housekeeping channel, the current design focuses on the building blocks for a single magnetometer channel. The performance limiting blocks are currently investigated and first circuit designs were made.
Electronics that operates in space is subjected to harsh environmental conditions like hard radiation and large temperature swings. In order to have a robust design, radiation hardness was investigated and semiconductor technologies were selected that can be made robust against radiation and where radiation-hardened digital libraries are available.
The design of two of the data-converters used in the newly developed ASIC will be presented along with the main challenges and proposed circuit implementations.
PublikationsstatusVeröffentlicht - 2018
VeranstaltungMicroelectronics Systems Symposium (MESS) 2018 - Vienna, Österreich
Dauer: 12 Apr. 201813 Apr. 2018


KonferenzMicroelectronics Systems Symposium (MESS) 2018

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