Abstract: A printed circuit board (PCB) includes first and second signal voids and a guard trace formed on a surface of the PCB. The first and second signal voids are for connecting to signal contacts of a high-speed data communication interface. The guard trace is located between the first signal void and the second signal void. The PCB further includes first, second, and third ground vias that couple the guard trace to a ground plane of the PCB. The first ground via is located at a first end of the guard trace. The second ground via is located at a second end of the guard trace. The third ground via is located between the first via and the second via.

Abstract: A printed circuit board (PCB) is provided for transmitting a differential signal. The PCB includes first and second conductive signal layers. The first conductive signal layer includes a first positive trace of the differential signal and a first negative trace of the differential signal. The second conductive signal layer includes a second positive trace of the differential signal and a second negative trace of the differential signal. The first positive trace is adjacent to the first negative trace, and the second positive trace is adjacent to the second negative trace and directly below the first negative trace.

Abstract: An add-in card printed circuit board (PCB) includes a body portion and a card edge portion. The body portion includes a circuit trace associated with a high-speed data communication interface. The card edge portion includes contact fingers, and is configured to be inserted into a card edge connector of an information handling system. The contact fingers include a signal contact finger coupled to the circuit trace, and a ground contact finger that is located adjacent to the signal contact finger. The ground contact finger includes a ground via that couples the ground contact finger to a ground plane layer of the add-in card PCB. The ground via is located half way within the body portion and half way within the card edge portion.

Abstract: A twin-axial cable is provided for high-speed data communication. The twin-axial cable includes a first conductor surrounded by a first portion of an incompressible insulating material and a second conductor surrounded by a second portion of the incompressible insulating material. The first and second conductors are arranged in line in a first axis at a distance apart. A profile of the first and second portions is an elongated profile along a second axis perpendicular to the first axis, such that a first height of the profile is greater than the distance.

Abstract: A high-speed signal subsystem testing system includes a processing system having a transmitter and a receiver, a loop back subsystem coupled to the transmitter and receiver to provide a testing communication path between the transmitter and the receiver, and a communication path testing engine coupled to the transmitter and the receiver. The communication path testing engine generates test signal(s) and transmits the test signal(s) via the transmitter and through the testing communication path provided by the loop back subsystem and, in response, receives test signal result(s) via the receiver and through the testing communication path provided by the loop back subsystem, The communication path testing engine processes the test signal result(s) to generate a testing impedance profile for the testing communication path, and compares the testing impedance profile to an expected impedance profile to determine whether a testing communication path issue exists in the testing communication path.

Abstract: A system may include a circuit board comprising a plurality of electrically-conductive layers separated and supported by layers of insulating material laminated together, wherein the plurality of electrically-conductive layers comprises a ground plane and the layers of insulating material comprise a surface layer having one or more openings through which the ground plane is exposed through the one or more openings. The system may also include a plurality of electrically-conductive pads formed on a surface of the surface layer and a cable comprising a first signal conductor mechanically contacted to a first pad of the plurality of electrically-conductive pads and a first drain conductor mechanically contacted to the ground plane through the one or more openings.

Abstract: A circuit board may include a plurality of electrically-conductive layers separated and supported by layers of insulating material laminated together and a via electrically coupled to a first layer of the circuit board and coupled to a second layer of the circuit board, the via comprising a first via portion comprising electrically-conductive material and having a first diameter and a first depth from a surface of the circuit board and a second via portion comprising electrically-conductive material and having a second diameter smaller than the first diameter and a second depth from the first depth.

Abstract: A high-speed signal subsystem testing system tests a processor transmitter and receiver coupled to a connector via a transmitter trace and a receiver trace, respectively. A transmitter test circuit on a testing board coupled to the connector compares a transmitter voltage received from the transmitter via the transmitter trace and the connector to a common mode voltage range and, in response to the transmitter voltage being outside the common mode voltage range, provides a transmitter trace issue signal. A receiver test circuit on the testing board coupled to the connector transmits a first test voltage towards the receiver, compares a second test voltage detected at the receiver test circuit in response to transmitting the first test voltage towards the receiver to a reference test voltage and, in response to the second test voltage being above the reference test voltage, provides a receiver trace issue signal.

Abstract: A system detects cracks in solder joints on a printed circuit board (PCB). The system includes a device, a signal generator, a termination resistor, and a detector. The device includes a first contact and a second contact coupled to the first contact. The device is soldered to the PCB by a first solder joint at the first contact and by a second solder joint at the second contact. The signal generator has a test signal output coupled to the first solder joint. The termination resistor has a first terminal coupled to the second solder joint, and a second terminal coupled to a ground plane of the PCB. The detector receives a reflected signal that is a reflection of the test signal from at least one of the first solder joint, the second solder joint, and the termination resistor. The detector provides an indication as to whether or not at least one of the first solder joint and the second solder joint is cracked based upon a magnitude of the reflected signal.

Abstract: A method may include receiving a first and a second complementary signal to provide differential signaling. The method may further include providing a first conductor trace to transport the first complementary signal; providing a second conductor trace to transport the second complementary signal, the second conductor trace immediately adjacent to the first conductor trace; providing a third conductor trace to transport the first complementary signal, the third conductor trace immediately adjacent to the second conductor trace; and providing a fourth conductor trace to transport the second complementary signal, the fourth conductor trace immediately adjacent to the third conductor trace.

Abstract: An information handling system includes a memory subsystem and a basic/input out system (BIOS). The BIOS performs multiple trainings of the memory subsystem, and each of the trainings is performed at a different temperature. The BIOS stores multiple derating values in a derating table of the BIOS, and each of the derating values corresponds to a respective tap value at a respective temperature. During a subsequent power on self test of the information handling system, the BIOS performs a first training of the memory subsystem, and stores a first set of tap values. During a runtime of the information handling system, a memory controller determines whether a temperature of the information handling system has changed by a predetermined amount. In response to the temperature changing by the predetermined amount, the memory controller utilizes the derating values in the derating table to automatically update the tap values.

Abstract: A circuit board may include a plurality of electrically-conductive layers separated and supported by layers of insulating material laminated together and a via electrically coupled to a first layer of the circuit board and coupled to a second layer of the circuit board, the via comprising a first via portion comprising electrically-conductive material and having a first diameter and a first depth from a surface of the circuit board and a second via portion comprising electrically-conductive material and having a second diameter smaller than the first diameter and a second depth from the first depth.

Abstract: Managing performance at a memory subsystem, including: performing DFE at a memory subsystem based on an initial number of taps and an initial tap value range, the memory subsystem including memory modules and memory channels connecting respective memory modules; determining, based on the initial number of taps and the initial tap value range, a channel margin of a particular channel of the memory subsystem; disabling, at the particular channel, a tap; calculating, based on the disabled tap at the particular channel, a reduction in the channel margin of the particular channel; comparing the reduced channel margin of the particular channel to a margin threshold; determining, based on the comparing, that the reduced channel margin of the particular channel is greater than the margin threshold; in response to determining that the reduced channel margin of the channel is greater than the threshold, retaining the tap at the particular channel.

Abstract: An aperiodically overlapping spiral-wrapped cable shield system includes a cable having cable components such as a pair of conductors, at least one insulator surrounding the pair of conductors, and at least one drain wire. The cable also includes a cable shield that is spirally wrapped around the cable components with a varying wrap pitch that provides a plurality of overlapping cable shield portions with varying overlap areas. When signals are transmitted using the cable components in the cable, the varying overlap areas of the plurality of overlapping cable shield portions create a plurality of varying LC circuits that are configured to generate a resonance that does not exceed a signal integrity resonance threshold for a signals.

Abstract: An information handling system includes a dual in-line memory module (DIMM) and a memory controller coupled to the DIMM via a data bus. The memory controller determines that a first lane of a byte group of the data bus is more susceptible to crosstalk than a second lane of the byte group, determines a first performance level of the first lane, changes a delay (D) of a third lane of the byte group, the third lane being adjacent to the first lane, and determines that a second performance level of the first lane is different from the first performance level in response to delaying the third lane.

Abstract: A high-speed transmission circuit comprises a connector pin that serves as part of a signal path, has a first conductivity, and has a connector pin leg that is coupled to a pad that has a second conductivity lower than the first conductivity. The connector pin leg and at least a portion of the pad form a resonant sub-circuit coupled to the signal path. The second conductivity causes a reduction in insertion loss in the signal path by damping a current in the resonant sub-circuit.

Abstract: A printed circuit board for an information handling system includes a trace, a routing component, and one or more intermediate components. The trace has a first impedance, and the routing component has a second impedance. The intermediate components have respective intermediate impedances. Each of the intermediate impedances has a corresponding value in a range between a value of the first impedance and a value of the second impedance. The one or more intermediate impedances reduce an impedance discontinuity between the trace and the routing component.

Abstract: An information handling system includes a memory controller and a dual in-line memory module (DIMM) coupled to the memory controller by a memory channel. The memory channel includes a plurality of single-ended multi-drop lanes arranged in a byte group. The information handling system determines, for each lane in the byte group, a tap setting for an associated decision feedback equalizer (DFE) of each lane. The information handling system further determines an average value for the tap settings for the lanes in the byte group, determines that a first tap setting for a first lane is different from the average value by greater than a threshold, and sets the first tap setting to the average value in response to determining that the first tap setting is different from the average value by greater than the threshold.

Abstract: An inhomogeneous dielectric medium high-speed signal trace system includes a first and second ground layer. A first dielectric layer is located adjacent the first ground layer. A second dielectric layer has a different dielectric constant and a greater thickness than the first dielectric layer, and is located between the first dielectric layer and the second ground layer. A first differential trace pair is located between the first dielectric layer and the second dielectric layer, and includes a trace spacing that is less than or equal to a thickness of the first dielectric layer. The first different trace pair transmit signals and, in response, produces a magnetic field, and the trace spacing prevents a magnetic field strength of the magnetic field from exceeding a magnetic field strength threshold at a second differential trace pair that is located adjacent the first differential trace pair.

Abstract: An inhomogeneous dielectric medium high-speed signal trace system includes first and second ground layers. A first dielectric layer has a first dielectric constant and is located adjacent the first ground layer, and a second dielectric layer has a second dielectric constant that is different than the first dielectric constant and is located between the first dielectric layer and the second ground layer. A first differential trace pair is located between the first and second dielectric layer. A plurality of first vias extend between the first ground layer and the second ground layer and are spaced part from each other and the first differential trace pair. A plurality of second vias extend between the first ground layer and the second ground layer, are spaced part from each other and the first differential trace pair, and are located opposite the first differential trace pair from the plurality of first vias.