We present a tunneling magnetoresistive (TMR) sensing microsystem consisting of a low flicker noise TMR sensor and a custom integrated readout frontend. The proposed sensor readout circuit introduces a novel ultra-low-noise current biasing scheme for the TMR sensor, which achieves a very low current noise floor of 2.2 pA/sqrt(Hz) for a 1mA biasing current. The TMR output voltage is processed by a differential readout scheme to improve the baseline-to-signal ratio. The microsystem also features an on chip 10-bit current DAC that allows compensating for the large process variations in the TMR base resistance value. The readout chip is manufactured in a 180nm SOI CMOS technology and heterogeneously integrated with the TMR sensor. The readout chain provides a thermal noise floor of 4 nV/sqrt(Hz), while, together with the biasing scheme, consuming a total power of 38mW. The complete sensor system consisting of the TMR and the readout circuit provides a state-of-the-art magnetic field noise floor of 120 pT/sqrt(Hz).
%0 Conference Paper
%1 mohamed2021readout
%A Mohamed, A.
%A Heidari, H.
%A Anders, J.
%B ESSCIRC 2021 - IEEE 47th European Solid State Circuits Conference (ESSCIRC)
%D 2021
%K iis myown
%P 1-4
%R 10.1109/ESSCIRC53450.2021.9567752
%T A readout circuit for tunnel magnetoresistive sensors employing an ultra-low-noise current source
%U https://ieeexplore.ieee.org/document/9567752
%X We present a tunneling magnetoresistive (TMR) sensing microsystem consisting of a low flicker noise TMR sensor and a custom integrated readout frontend. The proposed sensor readout circuit introduces a novel ultra-low-noise current biasing scheme for the TMR sensor, which achieves a very low current noise floor of 2.2 pA/sqrt(Hz) for a 1mA biasing current. The TMR output voltage is processed by a differential readout scheme to improve the baseline-to-signal ratio. The microsystem also features an on chip 10-bit current DAC that allows compensating for the large process variations in the TMR base resistance value. The readout chip is manufactured in a 180nm SOI CMOS technology and heterogeneously integrated with the TMR sensor. The readout chain provides a thermal noise floor of 4 nV/sqrt(Hz), while, together with the biasing scheme, consuming a total power of 38mW. The complete sensor system consisting of the TMR and the readout circuit provides a state-of-the-art magnetic field noise floor of 120 pT/sqrt(Hz).
@inproceedings{mohamed2021readout,
abstract = {We present a tunneling magnetoresistive (TMR) sensing microsystem consisting of a low flicker noise TMR sensor and a custom integrated readout frontend. The proposed sensor readout circuit introduces a novel ultra-low-noise current biasing scheme for the TMR sensor, which achieves a very low current noise floor of 2.2 pA/sqrt(Hz) for a 1mA biasing current. The TMR output voltage is processed by a differential readout scheme to improve the baseline-to-signal ratio. The microsystem also features an on chip 10-bit current DAC that allows compensating for the large process variations in the TMR base resistance value. The readout chip is manufactured in a 180nm SOI CMOS technology and heterogeneously integrated with the TMR sensor. The readout chain provides a thermal noise floor of 4 nV/sqrt(Hz), while, together with the biasing scheme, consuming a total power of 38mW. The complete sensor system consisting of the TMR and the readout circuit provides a state-of-the-art magnetic field noise floor of 120 pT/sqrt(Hz).},
added-at = {2021-06-29T10:02:51.000+0200},
author = {{Mohamed}, A. and {Heidari}, H. and {Anders}, J.},
biburl = {https://puma.ub.uni-stuttgart.de/bibtex/2a88bf850e2e6e1a973ea5f85ab9541e1/aymanmohamed},
booktitle = {ESSCIRC 2021 - IEEE 47th European Solid State Circuits Conference (ESSCIRC)},
doi = {10.1109/ESSCIRC53450.2021.9567752},
interhash = {d5003e061340de3b002151a15190b32a},
intrahash = {a88bf850e2e6e1a973ea5f85ab9541e1},
keywords = {iis myown},
month = {sept},
pages = {1-4},
timestamp = {2021-10-28T15:05:56.000+0200},
title = {A readout circuit for tunnel magnetoresistive sensors employing an ultra-low-noise current source},
url = {https://ieeexplore.ieee.org/document/9567752},
year = 2021
}
