A front-end ASIC for a 16-bit three-axis magnetometer for space applications based on anisotropic magnetoresistors

Abstract

Trabajo presentado a la XXVIII Conference on Design of Circuits and Integrated Systems celebrada en San Sebastián del 27 al 29 de noviembre de 2013.-- et al.Many space applications require the measurement of magnetic fields. This includes many scientific and meteorological instruments, as well as satellite attitude control systems. The most widely used method for measuring magnetic fields in space missions has been the use of fluxgate sensors, mainly due to their reliability, robustness and relatively small mass and volume with respect to the total size of the satellite. However, the current trends of cost reduction and standardization in aerospace technology tends towards the design of small satellites, commonly called nano-satellites or even pico-satellites, embodying a new challenge in the design of low-cost space instrumentation. In this scope, fluxgate sensors are massy and large enough so that their use is not addressable for these small satellites. This paper presents an alternative design of a three-axis magnetometer for the measurement of the strength and direction of an incident magnetic field in space applications, with a significant reduction in mass and volume while maintaining a high detectivity. The proposed system uses magnetic field sensors based on anisotropic magnetoresistances (AMR) and a radiation hardened by design (RHBD) mixed-signal ASIC that performs signal conditioning and analog to digital conversion up to 16 bits, and also handles calibration tasks, system configuration and communication with the outside. The use of an ASIC instead of discrete components reduces both weight and volume, and achieves improvements in performance and consumption. The proposed magnetometer provides high sensitivy to low magnetic fields up to 30 µG of resolution while offering a small, low cost and reliable solution for space applications.Peer Reviewe