Improvement Of Output Signals By Square Wave Driving In Planar Hall Resistance Sensor

In PHR sensor, PHR signals V-PHR was proportional to the driving current, V-DC and V-2f signals were caused by self field by sine wave driving current. The V-PHR and V-2f by sine wave driving were well fitted with calculated one by single domain model. The V-PHR by square wave driving were measured as the 1f, 3f, 5f .... signals, which higher order harmonics were included in square wave. The V-DC and V-DC(Squ) by sine and square wave driving showed same magnetic field dependence and V-DC(Sqc) = 2V(DC). The magnetic bead signals by square wave driving were 2 times higher than that by sine wave driving. Thus square wave driving can be used for the accuracy improvement of biosensors.