The present work analyzes a four-terminal Hall-plate device to determine the main sources of error and explain how current-spinning technique can be used to effectively reduce offset and noise. Based on this analysis, an improved magnetic sensor is designed using an eight terminal octagonal Hall plate and a chopped-based control circuit to implement the current-spinning technique. Since Hall plates are complete compatible with the CMOS manufacturing process, a monolithic chip which contains the sensor, switches, digital control and bias circuit were fabricated using a 0.6 μm commercial CMOS process. These devices are used to test the offset cancellation methodology and compare if there are advantages related to the device orientation or switching sequence. Experimental results show a residual offset of 0.25 mT, a 99% reduction compared with the original offset level measured at Hall plate. Gridchin, A.V., The four-terminal silicon piezotransducer: History and future (2004) 5th Annual International Siberian Workshop and Tutorial on Electron Devices and Materials, pp. 21-23Popovic, R.S., (2010) Hall Effect Devices, Second Edition, , Series in Sensors. Taylor and FrancisBilotti, A., Monreal, G., Vig, R., Monolithic magnetic hall sensor using dynamic quadrature offset cancellation (1997) IEEE Journal of Solid-State Circuits, 32, pp. 829-836Munter, P.J.A., A low offset spinning-current hall plate (1990) Sensors and Actuators, A21, pp. 743-746Ramirez, J., Fruett, F., Octagonal geometry hall plate designed for the PiezoHall effect measurement (2013) 28th Symposium on Microelectronics Technology and Devices-SBMICROCoraucci, G., Finardi, M., Fruett, F., A multi-terminal pressure sensor with enhanced sensitivity (2009) 5th International Conference on Solid-State Sensors, Actuators and Microsystems-TransducersKanda, Y., Migitaka, M., Effect of mechanical stress on the offset voltage of hall devices in Si IC (1976) Phys. Status Solidi, 35, pp. 115-118Munter, P.J.A., Electronic circuitry for a smart spinningcurrent Hall plate with low offset (1991) Sensors and Actuators, A27Udo, A., Limits of offset cancellation by the principle of spinning current Hall probe (2004) Proceedings of IEEE, 24, pp. 1117-1120Bellekom, S., Sarro, L., Offset reduction of Hall plates in three different crystal planes (1997) Solid State Sensors and Actuators, 1997. TRANSDUCERS '97 Chicago., 1997 International Conference on, 1, pp. 233-236. , Jun 1