Omnetics Fall 2018 Newsletter
In this Issue:
- Polarized Nano Connectors for Miniature Electronics
- Hybrid Nano-D Connector Family
- From the Engineer's Desk: Designing for Cat6A Ethernet
- Did you know?
- On the Road With Omnetics
Polarized Nano Connectors for Miniature Electronics
Polarized Nano (PZN) sized connectors from Omnetics minimize space while offering high signal integrity in today’s ruggedized applications. As our industry continues to focus on compact electronics modules, the miniature PZN series has gained more and more demand in the connector market. Omnetics can rapidly redesign a standard form to fit a wide variety of customer-specific applications. These ultra miniature connectors feature Omnetics’ military style pin and socket designs to provide uninterrupted electrical connections for portable applications that are exposed to high shock and vibration environments. Detailed information about Polarized Nano Connectors is available.
PZN connector contact spacing is set at .025" (.64 mm), and the design uses both male and female contacts in the same polarized insulator. The contacts are beryllium-copper and are plated with nickel and gold to ensure long-range performance. They utilize Omnetics’ flex-pin system for maximum durability. Teflon® insulated 32 gauge twisted copper wire offers maximum flexibility of the interconnect system. Interface mating and alignment is assisted by the design of the insulator shell. Most applications include surface or through-hole board mounted designs mated to fine wire plug sets. Omnetics began with contact counts ranging from 4 to 12 positions and can be configured in a number of standard tail types as well as modified to meet custom requirements. The newest design has been increased to 24 positions and beyond to accommodate unique high-signal count circuitry in portable miniature circuits. The insulator also has a critical alignment feature to ensure correct mating. A wide range of pin counts are available and p.c. board mounts fit standard printed circuit card design standards.
Today’s applications that demand PZN and other rugged ultra-miniature interconnects are varied across many industries. Modern medical designers are increasingly using the PZN format to squeeze more electronics into smaller devices used to monitor and provide patient services. PZNs are needed in small cameras in endoscopes and in neuro-links to send signals from the brain to other parts of our body. In space, PZNs connect to small sensors on giant separation ring assemblies to help measure torque on locking screws for rockets. Small solar arrays are also deployed using PZN connectors. F-1 race cars measure fuel rate consumption, large wind mills monitor and report lubricating oil levels, and towable sonar arrays use PZN interconnects because of their rugged versatility.
Compact reliability during all operating conditions in electronics is mandatory. Military surveillance camera circuits (for portable and remote weapon systems), portable computers (for remote mission systems), robotic hands, retracting arms, and even ground controlled robotics benefit from their rugged space saving design. One unique design, in particular, is aimed at down-hole electronic measurement technology. Another possible application for the PZN connector is Drive Circuits for Hand-held Laser and Orthopedic tools.
Custom connector design and solid models are available upon request. Miniature cabling is custom designed by Omnetics, or selected by the customer to meet the electrical requirements and fit the small size of the connectors. We are becoming a portable world and one that uses remote technology to work for us. PZN connectors serve that world well. Let’s all “think small”!
Hybrid Nano-D Connector Family
SWaP cables and connectors are designed to offer small Size, low Weight and Power to meet the exciting and dynamic growth of ruggedized miniature electronics. Omnetics has many years of experience with combining power sources and great signal integrity with modifications from our Nano connector line. We have now expanded and standardized many of our hybrid combo Nano-D connectors for the design engineer. This approach allows system designers to significantly offer dense circuit packaging and reduce the number of cables going to and from individual systems that also need power. Unlike a traditional Nano-D connector, these ruggedized high-density hybrid connectors come in a variety of configurations that include the traditional 1 Amp Nano contact along with 3 Amp Micro contacts to meet the application's power requirements. An additional advantage of using these combo power and signal connector and cable systems is low profile packaging.
This superior design still features a one-piece machined Nano-D shell and 200°C continuous operating temperature. We have simply modified our high reliability components from the standard Micro-D and Nano-D military specification products. The pin and socket system uses QPL quality spring pins made for BeCu that perform through high shock and constant vibration. Our insulators are designed using our best LCP and shells are of the same high reliability aluminum used in our Mil. Specification 83513 and Mil. Specification 32139 products. Designers can also pick from two, four, six, or eight position power contacts on the connectors. Drawing and specification details are readily available.
Omnetics' Hybrid/combo Nano-D connectors are ideally suited for mission critical applications that demand signal integrity as well as rugged and reliable harsh-environment performance. With small size and high signal density, these connectors are the perfect choice for electronic modules of applications that include: radars, weapon systems, communication gear, satellites, instrumentation, MWD tools, avionics, and other applications that require a smaller, high-density, rugged, high performance interconnect system. The family includes standard pin count sizes of 9, 15, 25, 31, and 51 positions wired to Teflon® insulated stranded wires. Size 32 gauge wire is used for signal technology, and size 26 gauge wire is included to handle the 3 amp sources for power. Horizontal board mount designs are readily available to standard printed circuit mounting standards and include mounting flange holes to ensure stability over the life of the circuit. Listings are coming soon for a complete view of the family. Also remember, tailored designs come much more quickly and easily using standard designs and materials. Contact our sales or design team for a session with our solid modeling team and design your own hybrid cable and connector.
From the Engineer's Desk: High Speed Connector Design
Designing Connectors for Cat6a Ethernet
There are two common Ethernet specifications that are mainstream in products today: Gigabit Ethernet (GigE) and 10 Gigabit Ethernet (10GigE or 10GbE). These protocols require cable assemblies that pass Cat5e and Cat6a requirements, respectively. As more and more networks transition to 10GbE, there is an increasing need to have Cat6a solutions that adequately pass these signals.
Cat6a Requirements & Challenges
The change from Cat5e to Cat6a introduces two main challenges: (1) The specifications for insertion loss, return loss, and crosstalk are tightened, and (2) the maximum frequency increases from 100 MHz to 500 MHz. These new specifications require a redesign of the connector, placing a stronger emphasis on contact spacing in order to balance the requirements for impedance and crosstalk.
500 MHz Bandwidth for 10 Gigabit Ethernet?
Many find it a surprise that cable assemblies for 10 Gigabit Ethernet require only 500 MHz of bandwidth. There are two main factors that make sense of this.
First, Ethernet signals are most often transmitted over four pairs, yielding a single lane data rate of 2.5 Gigabits per second. Second, a new signaling scheme called Pulse-Amplitude-Modulation (or PAM) is implemented. This allows more data to be transferred during each bit period. As an example, Figure 1 shows eye diagrams for three different types of signaling: (1a) traditional binary signaling; (1b) PAM-5 signaling used in Gigabit Ethernet, providing five different voltage levels; (1c) PAM-16 signaling used in 10 Gigabit Ethernet that transmits 16 different voltage levels.
In most standard connectors, pairs are generally too close to each other to meet the Cat6a crosstalk specifications. Based on this, the pinout must be optimized. Dozens of different potential designs are simulated to determine the best pin placement. This design is then manufactured and measured in the lab to compare performance to the Cat6a specification as described in TIA-568-C.2.
The optimal connector design requires the balancing of two critical parameters: crosstalk and impedance. Improved crosstalk is achieved by keeping pins within a pair close together, pins outside the pair far away, and grounds added wherever possible. Optimized impedance is generally achieved by increasing pin-to-pin spacing of a pair to reach 100Ω. Herein lies the tradeoff: increasing the pin-to-pin spacing within a pair degrades the crosstalk but improves the impedance. Through many iterations of simulation, the tradeoff that provides the best overall performance can be reached.
Importance of Cable-Connector Shield Termination
Good overall shielding effectiveness for a cable assembly is only achieved if the shield is properly terminated to the connector, on both ends of the harness. As a general rule, the overall shielding effectivess will be dictated by the size of the largest opening throughout the assembly (the smaller, the better). This large opening most often occurs at the cable-connector transition. In order to address this, it is important to maintain a termination across the full 360° of the cable-connector mate.
Omnetics offers custom circular solutions for Cat6a Ethernet. Figure 2 shows the pinouts for both the Micro 360® (left) and Nano 360® (right).
The cable is of course the other critical part of the assembly. Cables must also be designed specifically with crosstalk and impedance in mind. The pairs in proper designs will either be shielded or separated by a spline. The insulation diameter should be finely tuned and the pairs should be tightly twisted in order to maintain a constant distance between wires. Omnetics offers two different versions of the cable: a polyurethane-jacketed solution which is ideal for rugged environments, and a high-performance Gore cable, which is designed for aerospace.
More information on Omnetics' Micro 360® Cat6a is available.
Did you know?
Veteran's Day, recognized every November 11, honors America's Veterans for their service to their country. The day was chosen to recognize Armistice Day, or the end of World War I, which occurred on the 11th month on the 11th day at the 11th hour. (US Dept of Defense)
Thank you Veterans!
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