In an electronic device that employs high-speed differential signaling on one or more pairs of conductors in a flexible printed circuit, RF chokes are placed in the differential signal path and mounted directly on the flexible printed circuit which is used to interconnect a peripheral device, such as an image sensor, through a connector to another device component such as a main printed circuit board. The RF chokes are configured to suppress common-mode noise propagating in the differential pairs of conductors. In one illustrative embodiment, the RF chokes are located on the flexible printed circuit adjacent to the peripheral device to suppress common-mode noise near its source. In another illustrative embodiment, the RF chokes are mounted adjacent to the connector to suppress the common-mode noise before it has an opportunity to escape the flexible printed circuit at the major discontinuity presented by the connector.

A circuit board with a measure against high frequency noise includes: an interconnect substrate having an interconnect pattern to which an IC which is a source of high frequency noise is electrically connected; a pair of lands provided on a mounting surface of the interconnect substrate; and a chip component having a body composed of a magnetic body (i.e., ferrite) in a rectangular parallelepiped, and a pair of external electrodes provided at opposite ends of the body, the pair of external electrodes being connected to the pair of lands, the body being disposed on the interconnect pattern, as observed in a direction perpendicular to the mounting surface.

A method for forming a Z-directed component for insertion into a mounting hole in a printed circuit board according to one example includes filling a first cavity having a tapered surface with a body material. A first layer of a constraining material is provided on top of the first cavity and has a second cavity having a width that is smaller than the first cavity. The second cavity is filled with the body material. Successive layers of the constraining material are provided on top of the first layer of the constraining material. Cavities of the successive layers of the constraining material are selectively filled with at least the body material to form layers of the main body portion of the Z-directed component. The constraining material is dissipated to release the Z-directed component from the constraining material and the Z-directed component is fired.

A switched inductor DC-DC power converter chiplet includes a CMOS power switch, an LC filter, regulation circuitry, feedback control circuitry, and interface control circuitry integrated on a common substrate. The inductor for the LC filter can be formed on the same surface or on opposing surfaces of the substrate as the electrical terminations for the substrate. Another embodiment includes a switched inductor DC-DC power converter chiplet having a first powertrain phase and multiple second powertrain phases. When the load current is less than or equal to a threshold load current, the power conversion efficiency can be improved by only operating the first powertrain phase. When the load current is greater than the threshold load current, the power conversion efficiency can be improved by operating one or more second powertrain phases.

The disclosed technology relates to a power supply circuit that utilizes a double-sided printed circuit board (PCB) that has a first surface and a second surface. The second surface is disposed opposite the first surface. Mounted on the first surface is a first power stage and a first inductor. Mounted on the second surface is a second power stage and a second inductor. The second power stage is disposed opposite the first power stage. The second inductor is disposed opposite the first inductor.

In some implementations, an electronics system includes a voltage regulator circuit of a PDN configured to generate a power signal, a printed circuit board (PCB) comprising a power rail to deliver the power signal to a digital circuit generating an interfering signal. The PDN radiating the interfering signal or its harmonics impacting the functionality of destination antenna and circuits (such as Wi-Fi, Bluetooth, cellular, etc.). The system includes a filtering element configured to filter an interfering signal generated by the digital circuit. The filtering element includes a first set of low impedance (low-Z) segments and a second set of high impedance (high-Z) segments. The low-Z and high-Z segments are formed using a copper trace of the power rail and are serially connected to each other. The filtering element forms a low pass filter and filters out high frequency interfering signal going to the destination antenna and circuits by radiated means.

Disclosed herein are dual-spiral common-mode filters, printed circuit boards (PCBs) comprising such dual-spiral common-mode filters, and devices comprising such dual-spiral common-mode filters and PCBs. A dual-spiral common-mode filter is patterned into the reference plane of a PCB. The dual-spiral common-mode filter comprises a first spiral portion connected to a second spiral portion. The spiral portions may be substantially identical, or mirror images of each other, or different from each other. One or more signal traces in a signal trace layer of the PCB pass over the dual-spiral common-mode filter. The disclosed dual-spiral common-mode filters can replace both conventional patterned ground structure (PGS) filters used for radio-frequency interference mitigation and the cutouts often used in the reference plane of a PCB to mitigate impedance mismatches due to DC blocking capacitors. Also disclosed herein are methods of making PCBs that include dual-spiral common-mode filters.

A method of fabricating a printed wiring board (PWB) includes etching traces to carry direct current (DC) on a first surface of a first epoxy-based layer. The first epoxy-based layer includes radio frequency (RF) absorber material. The method also includes arranging a second epoxy-based layer. The second epoxy-based layer includes the RF absorber material and includes a first surface in contact with the first surface of the first epoxy-based layer such that the traces are sandwiched between the first epoxy-based layer and the second epoxy-based layer.

A filter module includes a first ground terminal, a second ground terminal, a low pass filter, and a second inductor. The low pass filter includes a first inductor provided in an input/output path of signal, a first capacitor provided in a first path connecting a first node and the first ground terminal, and a second capacitor provided in a second path connecting a second node and the second ground terminal. The second inductor is connected in series to the second capacitor in a path connecting the second capacitor and the second ground terminal. The first path and the second path are not connected to each other by any path except the one between the first node and the second node.

For circuit boards that may be used in computing devices, a horizontal inductor, or an array of such inductors, may be coupled to a circuit board having a plurality of signal routing lines in a second layer from a surface of the circuit board and the horizontal inductor is positioned over these signal routing lines and may generate magnetic field lines that directionally follow the signal routing lines. The horizontal inductor may have a coiled wire with a central axis that is oriented horizontally with the surface of the circuit board. The horizontal inductor, or an array of such inductors, may be coupled to a support board attached to the circuit board.