Philips Magnetoresistive Sensor manual KMZ10 and KMZ11 bridge configuration 2000 Sep

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Philips Semiconductors

Magnetoresistive sensors for

magnetic field measurement

General

MLC129

RT

 

RT

 

4

3

2

1

VCC

VO

GND

VO

In one pair of diagonally opposed elements the barber-poles are at +45˚ to the strip axis, with the second pair at −45˚. A resistance increase in one pair of elements due to an external magnetic field is matched by an equal decrease in resistance of the second pair. The resulting bridge imbalance is then a linear function of the amplitude of the external magnetic field in the plane of the permalloy strips normal to the strip axis.

This layout largely eliminates the effects of ambient variations (e.g. temperature) on the individual elements and also magnifies the degree of bridge imbalance, increasing sensitivity.

Fig 26 indicates two further trimming resistors (RT) which allow the sensors electrical offset to be trimmed down to zero during the production process.

Fig.26 KMZ10 and KMZ11 bridge configuration.

2000 Sep 06

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Contents General Contents Magnetoresistive sensors for Magnetic field measurementPhilips Semiconductors Operating principlesKMZ10 chip structure 2000 Sep Linearize Application Package Range Sensor FieldSensitivity 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 TA1 = 1 + Positive temperature coefficient TCGiven by 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
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