US 12,340,939 B2
Symmetric air-core planar transformer with partial electromagnetic interference shielding
Raul Blecic, Freising (DE); and Nicola Bertoni, Freising (DE)
Assigned to TEXAS INSTRUMENTS INCORPORATED, Dallas, TX (US)
Filed by Texas Instruments Incorporated, Dallas, TX (US)
Filed on Oct. 29, 2021, as Appl. No. 17/515,391.
Prior Publication US 2023/0138281 A1, May 4, 2023
Int. Cl. H01F 27/36 (2006.01); H01F 27/28 (2006.01)
CPC H01F 27/363 (2020.08) [H01F 27/2885 (2013.01)] 17 Claims
OG exemplary drawing
 
1. An apparatus comprising:
a substrate having a vertical stack of at least first, second, third, and fourth metal layers, the substrate including:
a first coil having at least a first loop in the first metal layer and at least a second loop in the second metal layer;
a second coil having at least a third loop on the third metal layer and at least a fourth loop in the fourth metal layer;
a first shield layer in the second metal layer; and
a second shield layer in the third metal layer.