Technology Overview

The core of Kandou’s innovative technology is a novel signaling method called Chord signaling™ which is based on a very general signaling and modulation theory centered around efficient circuit implementations. The theory is at the intersection of electronics, information theory, discrete mathematics and algorithm design. Chord signaling™ transmits correlated signals across multiple wires, the same way that differential signaling sends correlated signals across two wires. Unlike many other signaling methods like ternary signaling or PAM-4 signaling, Chord signaling™ exhibits the same performance with regard to intersymbol-interference as differential NRZ at a lower clock frequency.

Central to Chord signaling™ is the concept of a chordal code. One of the components of a chordal code is a set of vectors of the same length as the number of wires in the underlying interface, called the codebook. The vectors in a codebook correspond to values that are simultaneously transmitted on the wires. For example, for differential signaling, the codebook consists of the two-dimensional vectors (+1,-1) and (-1,+1), meaning that the values on the two wires in the interface are complementary. The second, equally important, components of a chordal code is a matched set of "multi-input comparators." As the name suggests, these vectors correspond to comparators that compare a linear combination of the values on some wires against another such linear combination.

More information on Chord signaling™ can be found here

To meet the stringent requirements of very high-speed SerDes links, Kandou has developed various methods, circuits, and topologies matched to Chord Signaling for tasks such as

  • Coded equalization
  • Matched low power CTLE/FIR/DFE
  • Crosstalk, SSO, EMI noise reduction
  • Power reduction (line power and receiver)
  • Mismatch tolerance
  • Efficient CDR
  • Efficient board routing
  • Clock embedding
  • Larger interfaces (through efficient coding algorithms)
  • Area minimization
  • Pin reduction
  • ….and more

Chord signaling™ is well suited to mobile and networking applications where traditional interfaces like PAM-4 and NRZ are approaching or have reached their technical limits.

Click here for downloadable documents that provide additional information on Kandou solutions.