Abstract: A multi-layer PCB has conductive vias (134) passing through multiple layers. A layer may have a conductive non-functional feature (710) physically contacting a via but not surrounding the via, to make the PCB more resistant to thermal stresses while, at the same time, reducing the parasitic capacitance compared to a prior art non-functional pad (310n).

Abstract: An information handling system includes an intrusion detection circuit having two inductors and an amplifier circuit. The amplifier circuit is configured to identify an increase in inductive coupling between the inductors in response to a change in position of a cover.

Abstract: A differential pair contact resistance asymmetry compensation system includes a differential trace pair that is provided on a board, a transmitter device that is coupled to the differential trace pair via a transmitter device connector interface, and a receiver device that is coupled to the differential trace pair via a receiver device connector interface. The receiver device receives, from the transmitter device via the differential trace pair, a contact resistance compensation data stream. The receiver device adjusts an impedance provided by the receiver device to compensate for a contact resistance asymmetry in at least the receiver device connector interface, and sets the impedance provided by the receiver device.

Abstract: A memory subsystem includes one or more communication channels that enable communication with more than one memory module of an information handling system (IHS). A memory controller of the memory subsystem is in communication with the one or more communication channels. In response to determining that one or more lines fail signal integrity testing at a target communication speed, the memory controller invokes an error checking and correcting (ECC) mode that reassigns lines of the communication channel for carrying data and ECC code. Lines that passed signal integrity testing are assigned to carrying data and ECC code. Lines that failed signal integrity testing are not used.

Abstract: An information handling system includes a first Dual In-Line Memory Module (DIMM) on a first memory channel of the information handling system, and a second DIMM on a second memory channel of the information handling system. A processor trains the first memory channel to a first speed based upon a first performance level of the first DIMM, trains the second memory channel to a second speed based upon a second performance level of the second DIMM, and allocates a portion of the first DIMM to the application based upon the first speed.

Abstract: A circuit board assembly of an information handling system has stepped diameter vias that carry communication signals through printed circuit board (PCB) substrates. Each stepped diameter via has a first barrel portion of a first diameter that is drilled through a first portion of the PCB substrates and that is at least lined with a conductive material to electrically conduct a selected one of: (i) a direct current and (ii) a communication signal from an outer layer to an internal layer of the more than one PCB substrate. Each stepped diameter via further includes a second barrel portion that extends from the first barrel portion deeper into the PCB substrates. The second barrel portion has a second diameter that is less than the first diameter and the smaller second diameter improves signal integrity (SI).

Abstract: An information handling system (IHS) has a circuit board assembly with a dual-sided interposer substrate that is inserted between a baseboard and a processor integrated circuit having a second pattern of electrical contacts. The dual interposer substrate formed of a stack of printed circuit boards (PCBs) provides communication channels between a first coupling pad on the baseboard that has a first pattern of electrical contacts and a second coupling pad on top of the dual interposer substrate that provides the second pattern of electrical contacts. The second pattern receives another type of processor integrated circuit than a type supported by the first pattern. Stacked vias formed through the stack of PCBs electrically connect respective electrical contacts of the first and second coupling pads to form a corresponding communication channel. One or more grounded vias mitigate signal integrity (SI) anomalies on the communication channels.

Abstract: A differential pair group equalization system includes a board providing a differential trace pair group with a plurality of differential trace pairs, each of a transmitter device and a receiver device are coupled to the board and the differential trace pairs in the differential trace pair group. At least one of the transmitter device and the receiver device operates to identify a first differential trace pair in the differential trace pair group, and adjust second differential trace pair equalization parameters for a second differential trace pair in the differential trace pair group. If it is determined that first differential trace pair signal transmission capabilities for the first differential trace pair have improved in response to the adjustment of the second differential trace pair equalization parameters for the second differential trace pair the second differential trace pair equalization parameters are set for the second differential trace pair.

Abstract: A dynamic random access memory (DRAM) device includes an on-die termination (ODT) controller including an input to receive an ODT signal from a memory controller, and ODT circuitry to terminate an interface circuit, the interface circuit to provide a data signal between the memory controller and the DRAM device. The ODT controller is configured in a first impedance switching mode to terminate the interface circuit at a first impedance level in response to a first state of the ODT signal, to terminate the interface circuit at a second impedance level in response to a second state of the ODT signal, and to terminate the interface circuit at a third impedance level in response to a change in the ODT signal from the first state to the second state, the third impedance level being between the first impedance level and the second impedance level.

Abstract: A dual-axial cable may include adjacent and substantially parallel first and second wires, each wire formed from an electrical conductor surrounded by a respective first and second electrical insulator having a lengthwise flat face outward side and having respective first and second inward sides of an interlocking structure, the first and second inward sides of the interlocking structure of the first and second electrical insulators mutually engaging to prevent a relative transverse displacement of the first and second wires and maintaining planar alignment of the flat face and electrical conductor of the first and second wires and to maintain the flat faces parallel to one another. The dual-axial cable may also include first and second drain conductors formed respectively on the flat faces of the first and second electrical insulators and running adjacent and substantially parallel to the first and second electrical conductors.

Abstract: An information handling system transmitter has a channel management module configured to negotiate and to lock a static transmitter equalization range. Control logic selects a setting adjustment for the locked transmitter equalization range; selects a variation type; applies the selected setting adjustment using the selected variation type, and instructs the transmitter channel management module to re-negotiate the updated transmitter equalization range. A receiver may negotiate and re-negotiate with the transmitter in order to receive the updated transmitter equalization range. The receiver may auto-adapt the updated transmitter equalization range to receive the transmitted data.

Abstract: A dual-axial cable may include adjacent and substantially parallel first and second wires, each wire formed from an electrical conductor surrounded by a respective first and second electrical insulator having a lengthwise flat face outward side and having respective first and second inward sides of an interlocking structure, the first and second inward sides of the interlocking structure of the first and second electrical insulators mutually engaging to prevent a relative transverse displacement of the first and second wires and maintaining planar alignment of the flat face and electrical conductor of the first and second wires and to maintain the flat faces parallel to one another. The dual-axial cable may also include first and second drain conductors formed respectively on the flat faces of the first and second electrical insulators and running adjacent and substantially parallel to the first and second electrical conductors.

Abstract: A method for manufacturing a surface mount technology (SMT) pad structure includes attaching an adjacent pair of differential contact strips to a nonconductive surface of respective landing pads of a surface mount technology (SMT) pad structure of a circuit board substrate, the pair of differential contact strips having converging narrowing at a respective distal end and each having a proximal signal trace for conducting a high-speed communication signal to another functional component attached to a circuit board substrate. The method includes attaching a return current strip that is longitudinally aligned adjacent to the pair of differential contact strips on a first lateral side and connected to a ground plane of the circuit board substrate, the converging narrowing of the adjacent differential contact strip increasing separation from a distal end of the return current strip, the separation improving signal integrity by reducing fringe effects, increasing impedance, and quenching resonance.

Abstract: In accordance with embodiments of the present disclosure, a circuit board may include a first trace formed in a first layer of the circuit board, a second trace formed in a second layer of the circuit board, a via, and a termination pad. The via may be configured to electrically couple the first trace to the second trace, the via comprising a via stub corresponding to a first portion of a length of the via not within a second portion of the via between a first location in which the first trace is electrically coupled to the via and a second location in which the second trace is electrically coupled to the via. The termination pad may be formed at an end of the via stub opposite at least one of the first location and the second location.

Abstract: A differential trace pair system includes a first conductive layer that is located immediately adjacent a first insulating layer. The system includes a second conductive layer that is located immediately adjacent the first insulating layer and opposite the first insulating layer from the first conductive layer, and includes an aperture that extends through the second conductive layer. A second insulating layer is located immediately adjacent the second conductive layer and opposite the second conductive layer from the first insulating layer. The system includes a first differential trace pair that is included in the second insulating layer and that includes a first differential trace that is positioned adjacent the aperture and references the second conductive layer, and a second differential trace that is longer than the first differential trace and that includes a first portion that is positioned adjacent the second conductive layer aperture and references the first conductive layer.

Abstract: A differential trace pair system includes a board having a first, a second, a third, and a fourth board structure member. A differential trace pair in the board includes a first differential trace extending between the first and the third board structure members, and a second differential trace extending between the second and the fourth board structure members. The differential trace pair includes a serpentine region that includes a first portion and a second portion where the first and the second differential traces have a first width, are substantially parallel, and spaced apart by a first differential trace pair spacing, and a third portion in which the second differential trace includes a second width that is greater than the first width, the first and second differential traces are substantially parallel and spaced apart by a second differential trace pair spacing that is greater than the first differential trace pair spacing.

Abstract: A printed circuit board includes a first trace, a second trace, and a first via. The first trace is in a first conductive layer. The second trace is in a second conductive layer. The first via interconnects the first trace and the second trace, and communicates a first signal from the first trace to the second trace through a third conductive layer. The third conductive layer has a higher impedance than the first conductive layer and the second conductive layer.

Abstract: In one or more embodiments, a circuit board may include a trace pair and a serpentine region of the trace pair, which may include: a first subregion in which the first trace includes a first portion that has a third width and a first length and in which the second trace includes a second portion, at least substantially parallel to the first portion, that has a fourth width, greater than the second width, and a second length; and a second subregion, adjacent to the first subregion, in which the first trace includes a third portion that has the third width and a third length and in which the second trace includes a third portion that has the fourth width and a third length, different from the second length.

Abstract: A serial data channel includes a transmitter that encodes serial data using a quaternary PAM-4 scheme, wherein the four PAM-4 signal levels include two balanced pairs of differential signal levels. The channel includes a de-emphasis circuit that determines that first and second symbols are in a first PAM-4 state, that a third symbol is in a second PAM-4 state, and provides a first de-emphasis to a voltage level of the second symbol in response to determining that the third symbol is represented as the second state. The de-emphasis circuit further determines that fourth and fifth symbols are in the second state, that a sixth symbol is in the first state, and provides a second de-emphasis to a voltage level of the fifth symbol in response to determining that the sixth symbol is represented as the first state. The first de-emphasis and the second de-emphasis represent different de-emphasis levels.

Abstract: An information handling system includes a first Dual In-Line Memory Module (DIMM) on a first memory channel of the information handling system, and a second DIMM on a second memory channel of the information handling system. A processor trains the first memory channel to a first speed based upon a first performance level of the first DIMM, trains the second memory channel to a second speed based upon a second performance level of the second DIMM, and allocates a portion of the first DIMM to the application based upon the first speed.