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 -