On the modelling of a CMOS magnetic sensor

Magnetic sensors are useful in applications such as magnetic read heads and non-contact current sensors. Ideally, a magnetic sensor should be easily integrated with its peripheral circuits. Experimental results indicate that it is possible to convert a conventional MOS transistor into a magnetic sensor by splitting the drain of the device into two. Such a device is attractive because the device is completely CMOS compatible. Integration of the sensor with electronic circuits can be easily achieved. However to realize such an integration, simulation model compatible with circuit simulators is essential. No such model has been reported. In this paper, we describe the development of a model for this split-drain MOS magnetic sensor which can be easily incorporated into popular circuit simulators such as SPICE. In developing this model, numerical simulations using symbolic mathematical tools are used to gain a physical understanding. The model is applicable for device operating in the linear region, and it is verified against experimental results