on chip applications the present invention on the other hand deals with voltage isolation transformers that are provided in integrated circuits ics and the problem of noise due to external electromagnetic interference that has plagued engineers and other people skilled in the art relating to circuit design and more specifically isolation devices used in ics the present invention proposes forming a primary winding and a secondary winding of a transformer each in the shape of a figure 8 the windings are etched during processing of the ic using photolithographic techniques as is known in the art in the embodiment shown in fig3 a primary winding 300 and a secondary winding 302 are formed to define traces running substantially parallel to each other and each defining a first clockwise helical coil and a second counter clockwise helical coil the first coil of the primary winding is defined in fig3 by reference numeral 310 the second coil of the primary winding by reference numeral 312 first coil of the secondary winding by reference numeral 320 and the second coil of the secondary winding by reference numeral 322 when a signal passes through the primary winding 300 it produces a magnetic field which couples with the secondary winding 302 to produce a current in the secondary winding on the other hand any external magnetic field or component thereof passing parallel to the axes of.