An integrated fluxgate device, comprising: a package substrate having a planar surface ; a circuit having transistors with active regions developed on the substrate and a metal layer formed above the active regions to provide interconnections for the transistors; a first integrated fluxgate die mounted on the planar surface of the package substrate above the metal layer, the first integrated fluxgate die including: a first semiconductor substrate ; a first integrated circuit formed on the first semiconductor substrate; and a first magnetic core formed above the first integrated circuit and oriented parallel to the planar surface of the package substrate ; and a second integrated fluxgate die mounted on the planar surface of the package substrate above the metal layer, the second integrated fluxgate die including: a second semiconductor substrate ; a second integrated circuit formed on the second semiconductor substrate; and a second magnetic core formed above the second integrated circuit and oriented orthogonally to the planar surface of the package substrate ; wherein the second integrated fluxgate die has a vertical edge , a first horizontal edge , and a mountable surface defined by the vertical edge and the first horizontal edge; and the second integrated fluxgate die is mounted to the package substrate by the mountable surface ; wherein the second magnetic core includes magnetic core segments aligned in parallel with each other and orthogonally to the vertical edge of the second integrated fluxgate die ; and wherein the first magnetic core has a contiguous core length; and each of the magnetic core segments of the second magnetic core has a segment core length approximately one-third of the contiguous core length. a package substrate having a planar surface ; a circuit having transistors with active regions developed on the substrate and a metal layer formed above the active regions to provide interconnections for the transistors; a first integrated fluxgate die mounted on the planar surface of the package substrate above the metal layer, the first integrated fluxgate die including: a first semiconductor substrate ; a first integrated circuit formed on the first semiconductor substrate; and a first magnetic core formed above the first integrated circuit and oriented parallel to the planar surface of the package substrate ; and a second integrated fluxgate die mounted on the planar surface of the package substrate above the metal layer, the second integrated fluxgate die including: a second semiconductor substrate ; a second integrated circuit formed on the second semiconductor substrate; and a second magnetic core formed above the second integrated circuit and oriented orthogonally to the planar surface of the package substrate ; wherein the second integrated fluxgate die has a vertical edge , a first horizontal edge , and a mountable surface defined by the vertical edge and the first horizontal edge; and the second integrated fluxgate die is mounted to the package substrate by the mountable surface ; wherein the second magnetic core includes magnetic core segments aligned in parallel with each other and orthogonally to the vertical edge of the second integrated fluxgate die ; and wherein the first magnetic core has a contiguous core length; and each of the magnetic core segments of the second magnetic core has a segment core length approximately one-third of the contiguous core length. <EOS>