An angle detector with a digital output is described. Thecomponent is meant as an alternative to the traditional slidepotentiometer used as volume control in many hearing aid applications.The component is based on the use of magnetic field sensitive MOSFETs(MAGFETs) detecting the position of a tiny bar magnet placed above asilicon chip. Because of the galvanic separation between the anglesetting bar magnet and the electrical circuit, this component isinsensitive to the rather hostile environment hearing aids are exposedto. The lifetime of the component is thereby increased significantly.The electrical circuit contains a switched current A/D-D/A conversionsystem for offset compensating the MAGFETs and for converting the MAGFETsignal currents into a digital output proportional to the input angle.It is implemented using a commercially available 1.5 μm CMOS process
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