-
- News
- Books
Featured Books
- design007 Magazine
Latest Issues
Current IssueOpportunities and Challenges
In this issue, our expert contributors discuss the many opportunities and challenges in the PCB design community, and what can be done to grow the numbers of PCB designers—and design instructors.
Embedded Design Techniques
Our expert contributors provide the knowledge this month that designers need to be aware of to make intelligent, educated decisions about embedded design. Many design and manufacturing hurdles can trip up designers who are new to this technology.
Manufacturing Know-how
For this issue, we asked our expert contributors to share their thoughts on the absolute “must-know” aspects of fab, assembly and test that all designers should understand. In the end, we’re all in this together.
- Articles
- Columns
Search Console
- Links
- Events
||| MENU - design007 Magazine
Moving From 28 Gbps NRZ to 56 Gbps PAM-4: Is it a Free Lunch?
September 24, 2018 | Yuriy Shlepnev, SimberianEstimated reading time: 1 minute
The usual way of signaling through PCB interconnects is a two-level pulse, an encoding of 1s and 0s or bits, named NRZ (non-return-to-zero) or PAM-2 line code type. Increasing the data rate with the NRZ code type presents some obstacles. For a 28 Gbps NRZ signal, the bit time is about 35.7 ps with the main spectral lobe below 28 GHz. For a 56 Gbps NRZ signal, the bit time is about 17. 86 ps, with the main spectral lobe below 56 GHz.
One can feel the problem already: Getting PCB interconnect analysis and measurements up to 56 GHz and beyond is very challenging, to say the least. In addition, the expected attenuation (dielectric, conductor and roughness losses) would also be an obstacle for 56 GHz NRZ. To reduce the bandwidth of the signal, pulse amplitude modulation with four levels (PAM-4) is being used more frequently on production boards.
Instead of single bits, symbols 00, 01, 10, and 11 are coded by four levels of the pulse and the symbol time is twice as large as the bit time for NRZ signal with the same data rate; that is about 35.7 ps for 56 Gbps PAM-4—the same as for 28 Gbps NRZ! If we know how to design interconnects that correlate with the measurements for 28 Gbps NRZ, is it going to be a free lunch to move to 56 Gbps NRZ?
To read this entire article, which appeared in the August 2018 issue of Design007 Magazine, click here.
Suggested Items
Cogiscan Collaborates with Koh Young to Unveil how its Factory Insights Software Transforms Data into Action at IPC APEX Expo
03/28/2024 | Koh YoungKoh Young, the industry leader in True3D measurement-based inspection solutions, is excited to announce Factory Insights, the latest offering from Cogiscan, will be demonstrated alongside KSMART in Koh Young booth 2112 during IPC APEX Expo.
ASMPT to Exhibit Smart Manufacturing at IPC APEX EXPO 2024
03/27/2024 | ASMPTWith its innovative, data-driven Intelligent Factory concept and a comprehensive hardware and software portfolio around SMT production, market and innovation leader ASMPT will be a major presence at the IPC APEX EXPO 2024, the industry’s main event in California.
Semtech Pioneers the Path to 6G with Advanced 5G Wireless Technologies
03/27/2024 | BUSINESS WIRESemtech Corporation, a leader in high-performance semiconductors, IoT systems and cloud connectivity services, unveiled its latest innovations poised to shape the future of 5G and pave the way for 6G.
IDC: Half of Asia’s Top Firms to Embrace AI-Driven Headless BI and Analytics by 2026
03/27/2024 | IDCA recent IDC FutureScape report, IDC FutureScape: Worldwide Data and Analytics 2024 Predictions — Asia/Pacific (Excluding Japan) Implications, highlights that by 2026, 50% of Asia/Pacific-based Top 2000 organizations (A2000) will adopt AI-driven headless BI and analytics with chat, Q&A, and proactive notification functionality, quadrupling the number of users with access to contextual information.
AT&S Well Prepared to Benefit from AI Boom
03/26/2024 | AT&SThe rapid progress in the development of artificial intelligence promises to revolutionize all areas of daily life in the coming years. In order to operate such AI systems, an enormous amount of computing power is required, which is provided by a vast network of data centres.