Temperature coefficient improvement for low noise magnetic measurements in LISA

Previous research with Anisotropic Magnetoresistive sensors (AMR) have shown significant improvements for weak magnetic field applications using dedicated noise reduction techniques in the signal conditioning circuit. However, an important source of error that must be addressed is the thermal dependence of the sensor system, more significant in the AMR sensitivity. The external temperature fluctuations affect the output of the sensors due to the temperature coefficient of the magnetoresistors, which may cause an increase of the estimation of the noise spectral density at low frequencies. Ongoing research using a low noise/low temperature coefficient current source to supply the sensor's bridge enhances the thermal performance of the sensors at the lower end of the LISA bandwidth. Preliminary results are shown in this paper.