KMZ51 (Philips) Magnetic field sensor

FEATURES

• High sensitivity

• Integrated compensation coil

• Integrated set/reset coil.

APPLICATIONS

• Navigation

• Current and earth magnetic field measurement

• Traffic detection.

DESCRIPTION

The KMZ51 is an extremely sensitive magnetic field sensor, employing the magnetoresistive effect of thin-film permalloy. The sensor contains one magnetoresistive Wheatstone bridge and integrated compensation and set/reset coils. The integrated compensation coil allows magnetic field measurement with current feedback loops to generate an output that is independent of drift in sensitivity. The orientation of sensitivity may be set or changed (flipped) by means of the integrated set/reset coil. A short current pulse should be applied to the compensation coil to recover (set) the sensor after exposure to strong disturbing magnetic fields. A negative current pulse will reset the sensor to reversed sensitivity. By use of periodically alternated flipping pulses and a lock-in amplifier, output is made independent of sensor and amplifier offset.