MAGNETIC SENSOR DEVICE WITH GAIN STABILIZATION

摘要

The invention relates to a magnetic biosensor (10) with a magnetic field generating wire (11) and a magnetic sensor element in the form of a GMR sensor (12) that is driven with a sensor current (I2). An evaluation unit (30) comprising a band-pass filter (31), an amplifier (32) and a processing circuit (33) measures the amount of 1/f noise in the sensor signal (UGMR), from which the sensor gain can be determined. Said sensor gain can then be used for normalizing ordinary measurements of the biosensor (10), thus stabilizing these measurements against gain variations.