Analysis of the offset of semiconductor vertical Hall devices

This study investigates the origin of the offset voltage of five-contact vertical Hall sensors (5C-VHS) by modeling these devices as a simple lumped resistor circuit. The model with the shape of a four-contact Wheatstone bridge was enhanced by asymmetries caused by the mismatch of the lumped resistors. Further, the junction field effect was taken into account by modulating the resistances of the lumped elements with the average of the voltages applied at their contacts. The linear and quadratic components of the offset versus drive voltage characteristics in four operation modes were successfully traced back to the modeled asymmetries and nonlinearities. The measured offset characteristics of 5C-VHS is satisfactorily described and methods for reducing this undesired signal component are inferred.