Development of chopper-stabilized ASIC preamplifier for improving noise equivalent magnetic induction of search coil magnetometer probing space plasma waves

Abstract Space-based search coil (SC) magnetometers connected to preamplifiers have been used investigate magnetic field vectors of plasma waves from 100 mHz 10 kHz for understanding magnetospheric dynamics. However, flicker noise below several Hz typical degrades the equivalent induction (NEMI) SCs and affects probing Hz. In this study, we developed a chopper-stabilized preamplifier using application-specific integrated circuit (ASIC) technology improving NEMI while maintaining miniaturization low power consumption. The chopper ASIC fits into layout size 2.3 × 3.4 mm in bare chip. We two SC sensors with different (20 cm 5 cm) lengths evaluate prototype preamplifier. At mHz, values 20-cm length 5-cm were 0.1 nT/Hz 1/2 1.9 , respectively, which can detect electromagnetic ion cyclotron magnetosphere. value at 5-cm-length was improved by approximately 19 dB compared that previous without chopping. conducted temperature tests behavior under wide range − 40 + °C. coefficient gain 0.02 dB/°C, is sufficiently temperature-dependence. use achieved high stability radiation tolerance. Thus, robustness ultra-low characteristics suitable wave observations harsh space environments future missions. Graphical