Apparatus and method using a plurality of magnetic field sensitive devices

An apparatus comprising:

• a plurality of magnetic field sensitive devices comprising at least a first magnetic field sensitive device, a second magnetic field sensitive device and a third magnetic field sensitive device;
• and
• a power supply,
• wherein the first to third magnetic field sensitive devices are coupled to each other and to the power supply such that a first supply current path runs through the first magnetic field sensitive device and not through the second magnetic field sensitive device, a second supply current path runs through the second magnetic field sensitive device and not through the first magnetic field sensitive device, and the first and second current paths run through the third magnetic field sensitive device, and
• wherein an internal resistance which the third magnetic field sensitive device provides to a first supply current is smaller than an internal resistance which the first magnetic field sensitive device provides to a second supply current and which the second magnetic field sensitive device provides to a third supply current.

A method for detecting a magnetic field using an apparatus comprising a plurality of magnetic field sensitive devices each having at least three terminals and grouped in N groups, with N>1, wherein each group k comprises 2k-1 magnetic field sensitive devices, for 1≦k≦N, wherein the plurality of magnetic field sensitive devices are coupled such that, for 1<k≦N, supply currents flowing through two magnetic field sensitive devices in group k flow through one magnetic field sensitive device in group k−1, the method comprising:

• providing a supply current independently through each magnetic field sensitive device of group N;
• tapping an output signal at at least one contact of at least one magnetic field sensitive device of each group k of the N groups;
• and
• combining each tapped output signal into an overall output signal representing a measurement of the magnetic field.