Low-frequency noise in planar Hall effect bridge sensors
(English)Manuscript (preprint) (Other academic)
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 400 Hz. The 1/f-like excess noise can be described by the phenomenological Hooge equation with a Hooge parameter of gH=0.016. The detectivity is shown to depend on the total length, width and thickness of the bridge branches. Increasing the total length by a factor of 10 improves the detectivity by a factor of 101/2. 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.
Magnetoresistance, Planar Hall effect, Low-frequency noise, Detectivity
Research subject Engineering Science with specialization in Solid State Physics; Engineering Science with specialization in Microsystems Technology
IdentifiersURN: urn:nbn:se:uu:diva-153314OAI: oai:DiVA.org:uu-153314DiVA: diva2:416044
FunderKnut and Alice Wallenberg FoundationSwedish Research Council