Two-dimensional magnetic microsensor with on-chip signal processing for contactless angle measurement

The reported CMOS microsystem is the key element for accurate angle measurements. In combination with a permanent magnet, it is used for various wear free angular positioning control systems for automotive and industrial applications covering the full 360 degrees range. The integrated system includes a two-dimensional (2-D) magnetic microsensor (30 x 30 mu m(2) active area, offset compensation, and signal conditioning circuitry, A navel approach for the angle calculation is presented using an on-hoard incremental ADC, A, bitstream representing the angular position of the applied permanent magnet is provided at the system output. The system achieves a 1 degrees angular resolution with 9 nW power consumption and a permanent magnet of 100 mT. The chip is fabricated in a generic 2-mu m, double-poly. double-metal CMOS process and covers an area of 2.6 x 4.1 mm(2).