Design Of Digital Magnetic Sensor Chip

The giant magnetoresistance(GMR)is an effect that small magnetic field changes can cause much larger resistance variation of the certain magnetic material than usual,which is found by Fert and Grunberg in 1988 separately.The GMR device is firstlyly used as readhead of the harddisk,which greatly improved the storage density,and promoted the rapid development of modern computer technology.Besides,the GMR effect is also applied as magnetic sensor to detect the magnitude,direction,graduation,etc.The magnetic sensor based on GMR has been widely used in automotive electronics,intelligent transportation,smart grid,industrial control,Internet of things,aerospace,medical electronics,Home appliances,consumer electronics and other fields.Such as road traffic detection,parking lot parking detection,magnetic encoder,contactless magnetic potentiometer,gear speed sensor,etc.GMR gear sensor is with high sensitivity,good linearity,small hysteresis and other advantages.The paper proposed an integrated gear sensor that to detect the speed of the rotating gear by sensing the variation of the magnetic field,with acquisition circuit is designed for the sensor signal processing.The gear sensor a new type of integrated speed sensor which is achieve by System-in-Package technology.The paper based on the characteristics of GMR magnetoresist and CSMC 1um40V HVCMOS,the circuit design and simulation of the design scheme are carried out in the Tanner software environment.After the modules and systems meet the design specifications,respectively,the magnetic chip and conditioning chip layout design.After the completion of the chip,the chip using multi-core package,the test analysis to meet the design requirements can work properly.