With Shielding Patents (Class 330/170)
  • Patent number: 8030763
    Abstract: A semiconductor package (20) includes circuits (22, 24). The circuit (22) includes electrical devices (52, 54) interconnected by a bondwire array (62). Likewise, the circuit (24) includes electrical devices (58, 60) interconnected by a bondwire array (64). Signal wires (76) of the bondwire array (62) are proximate to signal wires (78) of the bondwire array (64). Ground wires (66, 68) are located on either side of, and close to, bondwire array (62). Ground wires (70, 72) are located on either side of, and close to, bondwire array (64). The ground wires (66, 68, 70,72) are electrically coupled to a ground region (74). The ground wires (66, 68, 70, 72) reduce a magnetic flux density (140) via induced return currents (126, 130) on the ground wires of opposite polarity to signal currents (124, 128) on the bondwire arrays (62, 64) to reduce inductive coupling between the adjacent bondwire arrays (62, 64).
    Type: Grant
    Filed: June 26, 2008
    Date of Patent: October 4, 2011
    Assignee: Freescale Semiconductor, Inc.
    Inventors: Manuel F. Romero, Peter H. Aaen
  • Patent number: 4124822
    Abstract: A DC isolation amplifier having improved conductive isolation between its input and output. The amplifier includes an input section having a modulator and an output section having a demodulator and an oscillator section. The modulator and demodulator are nonconductively coupled through inductive loops of two closed-loop cores of magnetic material each having windings inductively coupled to the material of their associated core and to the other of the modulator or the demodulator. Additionally, a unitary closed loop winding couples the two cores such that the net EMF induced in the turns of the winding accordingly such that the respective component of the external magnetic field of the turns is substantially normal to the respective plane of each turn of this plurality. Additionally, this unitary loop is twisted between the cores to comprise a twisted pair additionally to minimize the effects from external magnetic fields. In the preferred embodiment, this loop is limited to two turns per core.
    Type: Grant
    Filed: September 16, 1977
    Date of Patent: November 7, 1978
    Assignee: American Optical Corporation
    Inventor: Thomas K. Naylor