An integrated chip coil sensor and instrumentation amplifier for bio-magnetic signal acquisition

This paper presents a miniaturized magnetic sensor chip for bio-magnetic signal measurements. The sensor fabricated in 0.18 μm CMOS process embeds an inductance coil and instrumentation amplifier that provides excellent sensitivity and low reference noise level in comparison to the state of art. The integrated sensor with frequency band between 50 Hz and 5 KHz illustrates bandpass filter characteristics which attenuates the low and high frequency noise from the external environment. The signal sensitivity of the device is 3.2 fT/μV and inferred noise at 300 Hz is 29 fT/√Hz. The sensor is used for bio-magnetic signal acquisition.