Magnetic senor digital processing interface for electrical motor application

摘要

A system and methods for an interface for magnetic sensors to determine a rotational angle has been achieved. Said interface can be used for any kind of magnetic sensors providing analog signals of the sine and cosine values of the angle to be determined. Said analog signals are being processed in two measurement paths for the sine and cosine signal each until the desired angle is computed by a CORDIC processor. The first stage of said measurement path is the conversion of the sine and cosine signals from analog to digital by 2<nd >order delta-sigma modulators with an over-sampling ratio. A low-pass decimation filter with sinc<3 >characteristic performs the digital value computation. The next stage normalizes the digitized sine and cosine values to correct offset and scaling deviations. Said CORDIC processor computes the angle to be determined by decomposing the desired rotation angle into iterations of pre-defined elementary rotation angles performing the rotation operation by simple shift-and-add operations replacing multiplication/division operations and the magnitude of the vector MAG={square root}{square root over (sin<2>+cos<2>)} using the output from said pair of normalization stages.