TY - JOUR
T1 - Low-frequency noise in planar Hall effect bridge sensors
AU - Persson, Anders
AU - Bejhedb, R.S.
AU - Bejhed, R.S.
AU - Nguyen, H.
AU - Gunnarsson, K.
AU - Dalslet, Bjarke Thomas
AU - Østerberg, Frederik Westergaard
AU - Hansen, Mikkel Fougt
AU - Svedlindh, P.
PY - 2011
Y1 - 2011
N2 - The low-frequency characteristics of planar Hall effect bridge sensors are investigated as function of the sensor bias current and the applied magnetic field. The noise spectra reveal a Johnson-like spectrum at high frequencies, and a 1/f-like excess noise spectrum at lower frequencies, with a knee frequency of around 400Hz. The 1/f-like excess noise can be described by the phenomenological Hooge equation with a Hooge parameter of γH=0.016. The detectivity is shown to depend on the total length, width and thickness of the bridge branches. The detectivity is improved by the square root of the length increase. Moreover, the detectivity is shown to depend on the amplitude of the applied magnetic field, revealing a magnetic origin to part of the 1/f noise.
AB - The low-frequency characteristics of planar Hall effect bridge sensors are investigated as function of the sensor bias current and the applied magnetic field. The noise spectra reveal a Johnson-like spectrum at high frequencies, and a 1/f-like excess noise spectrum at lower frequencies, with a knee frequency of around 400Hz. The 1/f-like excess noise can be described by the phenomenological Hooge equation with a Hooge parameter of γH=0.016. The detectivity is shown to depend on the total length, width and thickness of the bridge branches. The detectivity is improved by the square root of the length increase. Moreover, the detectivity is shown to depend on the amplitude of the applied magnetic field, revealing a magnetic origin to part of the 1/f noise.
KW - Detectivity
KW - Magnetoresistance
KW - Low-frequency noise
KW - Planar Hall effect
U2 - 10.1016/j.sna.2011.09.014
DO - 10.1016/j.sna.2011.09.014
M3 - Journal article
VL - 171
SP - 212
EP - 218
JO - Sensors and Actuators A: Physical
JF - Sensors and Actuators A: Physical
SN - 0924-4247
IS - 2
ER -