A Novell Hall Magnetometer Using Dynamic Offset Cancellation

Abstract

A novel Hall magnetometer using dynamic offset cancellation principle is presented. It consists from a single triangular silicon plate with three contacts and interface electronics. The proposed dynamic offset-cancelling measurement cycle includes three states. During each state, an external circuit is switched to the plate contacts in a certain way. This way, the direction of current flow through the Hall plate is changed from phase to phase. At the same time, the output voltage is measured. After averaging the obtained three voltages per a measurement cycle, the offset voltage cancelled and this way the offset-free Hall voltage is obtained. The obtained offset reduction factor is very promising, reaching 120–130. The Hall device sensitivity is about 25 V/AT.

Keywords

• dynamic offset cancellation
• hall magnetometer
• sensor interface electronics