Low-Frequency Noise Correlation in Current-Mode Magnetic Transducers: The CHOPFET Case

This paper is about low-frequency noise correlation in current-mode magnetic field transducers. The analysis methodology specifically focuses on the chopper-stabilized MAGFET (CHOPFET), a magnetotransistor that is compatible with the spinning current technique for low-frequency noise and offset cancelation.Experiments performed on a prototype circuit fabricated in the Austria Mikro Systeme 0.35 μm CMOS process show a minimum value of 0.75 noise correlation between the two consecutive switching phases on an arbitrary-chosen terminal and whatever the operation region of the CHOPFET. This includes the contributions of uncorrelated sources, which cannot be separated from the correlated ones in the analysis process.