Magnetic Line Array Cmos Sensor Ic

Semiconductor magnetic sensor based on silicon is now widely used in many fields as automotive, medical or process control; in particular, magnetic field sensors can be used for on-chip contact-less current measurements. Traditional magnetic sensor is not integrated with the signal processing circuits in one chip, but is soldered with the discrete signal processing circuits. In this way, it's difficult to realize the microminiaturization, systematization and smart sensor.In this paper, a novel magnetic sensor array IC has been designed and fabricated by the standard CMOS technology. It realized the integration of the sensor array and processing circuits on the same chip according with the development direction of SOC and smart sensor. In this chip, the Magnetic sensor cell is implemented with a novel sector split drain MOSFET transistor (sector MAGFET), which can directly transfer magnetic signal into current output signal. The sector MAGFET was first suggested, and its improvement of the sensitivity is attributed to this novel structure. The sensor structure is optimized with the founding of the sensitivity model of the sector MAGFET. In the signal processing system, the function of pre-processing circuits is to control the effect on the chip of the magnetic field; the correlated double sampling (CDS) circuits greatly reduce the fixed pattern noise (FPN) and improve the signal-noise ratio (SNR); the changeable reset frequency scanning circuits enhance the dynamic range of the detected magnetic field. All the sensor system is operated under the control of the digital control circuits.The maximum sensor sensitivity of 3.77%/T of the sector MAGFET is obtained by the experimental results, which is higher than the CMOS rectangle MAGFET already reported. The sensitivity of the sensor system is 98.5mV/(us-T) and the range of the detected magnetic field is from 0.01T to 2T. The design of the chip is advance in the relative researches.