1 research outputs found
A CMOS Analog Front-End for Tunnelling Magnetoresistive Spintronic Sensing Systems
This paper presents a CMOS readout circuit for
an integrated and highly-sensitive tunnel-magnetoresistive
(TMR) sensor. Based on the characterization of the TMR sensor
in the finite-element simulation, using COMSOL Multiphysics,
the circuit including a Wheatstone bridge and an analogue
front-end (AFE) circuit, were designed to achieve low-noise and
low-power sensing. We present a transimpedance amplifier
(TIA) that biases and amplifies a TMR sensor array using
switched-capacitors external noise filtering and allows the
integration of TMR sensors on CMOS without decreasing the
measurement resolution. Designed using TSMC 0.18 μm 1V
technology, the amplifier consumes 160 nA at 1.8 V supply to
achieve a dc gain of 118 dB and a bandwidth of 3.8 MHz. The
results confirm that the full system is able to detect the magnetic
field in the pico-Tesla range with low circuit noise
(2.297 pA/√Hz) and low power consumption (86 μW). A
concurrent reduction in the power consumption and attenuation
of noise in TMR sensors makes them suitable for long-term
deployment in spintronic sensing systems