This paper explains how 224 Gbps PAM4 systems differ from previous generations in terms of interconnects, what technologies and methodologies enable 224 Gbps PAM4 interconnects, and what may be required to reach beyond 224 Gbps. Successfully delivering 224 Gbps PAM4 signals requires careful analysis of signal integrity and thermal effects. But to understand why it has become ubiquitous in serial data standards, you first must understand the market forces driving the data networking industry. In this article, I will explore. AN 835: PAM4 Signaling Fundamentals - This application note explains PAM4 theory and its operation. This data rate doubling is not achieved by doubling the clock directly, but rather by doubling the baud rate through higher order 4-level pulse amplitude modulation. PAM4 is a branch of the pulse amplitude modulation (PAM) technology, which is a mainstream signal transmission technology following non-return-to-zero (NRZ). Playing a key role in multi-order modulation, PAM is widely used in high-speed signal interconnection.
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