Philips Magnetoresistive Sensor manual KMZ10 chip structure 2000 Sep

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Philips Semiconductors

Magnetoresistive sensors for

magnetic ﬁeld measurement

General

handbook, halfpage	R

H

MLC128

Fig.3 The resistance of the permalloy as a function of the external field.

In this basic form, the MR effect can be used effectively for angular measurement and some rotational speed measurements, which do not require linearization of the sensor characteristic.

In the KMZ series of sensors, four permalloy strips are arranged in a meander fashion on the silicon (Fig.4 shows one example, of the pattern on a KMZ10). They are connected in a Wheatstone bridge configuration, which has a number of advantages:

∙Reduction of temperature drift

∙Doubling of the signal output

∙The sensor can be aligned at the factory.

handbook, full pagewidth

MBC930

Fig.4 KMZ10 chip structure.

2000 Sep 06

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Image 4

Contents General Contents Magnetoresistive sensors for Magnetic ﬁeld measurementPhilips Semiconductors Operating principlesKMZ10 chip structure 2000 Sep Sensor Field SensitivityLinearize Application Package Range TypeSensor characteristics FlippingEffect of temperature on behaviour 25 oC Amb MV/V 75 oC 125 oC Operating range KA/m Using magnetoresistive sensors KMZ10BFurther information for advanced users + Δ R ⎛ H For R 8 = R 2R TPositive temperature coefficient TC Given byA1 = 1 + Magnetoresistive sensorResistance- ﬁeld relation Appendix 1 the Magnetoresistive EffectSinφcosφ Magnetization of the thin layer LinearizationSensitivity Materials Materials 10−8Ωm Δρ/ρ% ΙΙkΔ/mThis also considerably enlarges Hk. If a small temperature Appendix 2 Sensor FlippingSensor output ‘Vo’ as a function of the transverse ﬁeld Hy Appendix 3 Sensor Layout KMZ10 and KMZ11 bridge configuration 2000 Sep Weak Field Measurement ContentsFundamental measurement techniques Flipping coil T flipping current if Time Internal magnetization Sensor Temperature Drift 25 oC Flipping coil Sensor KMZ10A1 Technique Effect