Passive equalizers augment transmission performance

Chrontel Inc. has announced a new series of CH6000 passive equalizer devices designed to enhance performance of high data-rate transmission media. CH6000 devices can compensate for transmission losses that plague popular interconnects at data rates up to 5Gbit/s. These new devices are ideally suited for HDMI, DisplayPort and other high-speed cabling, and for FR4 PCBs used as backplane system interconnects.

The copper used as a transmission medium in cables and the FR4 material used as an insulator in PCBs act like low-pass filters that attenuate high frequency components of a high-speed digital signal. This attenuation introduces inter-symbol interference at gigabit data rates—closing the symbol "eye" that defines the data transmission. CH6000 devices are passive network high-pass filters that create an inverse channel response, which counteracts the low-pass characteristics inherent in copper and FR4. By incorporating a CH6000 device, the transmission medium achieves an essentially flat frequency response over the entire gigabit frequency spectrum required for HDMI, DisplayPort and other high-speed protocols.

Low-cost solution
"With the proliferation of HDMI, DisplayPort and other high data-rate protocols, which are essential for digital video transmission and networking, the physical limitations of copper connections are increasingly revealed," said David Soo, Chrontel president and CEO. "Our customers needed a very low-cost way to improve transmission performance without adding complexity to their PC and CE systems. Hundreds of millions of cables and PCBs produced annually can benefit from the incorporation of passive equalization technology."

CH6000 devices are passive equalizers that require no power or ground connections. They can be placed anywhere in the data path, providing great flexibility in routing and placement design. The devices are protocol independent, offering bi-directional operation and loss compensation for any differential signal.

Chrontel CH6000 samples are currently available, and production volumes will be available in March 2009. CH6000 devices are available in 4-pin LFCSP/LPCC packages and are priced at $0.50 in 10,000-piece quantities.

- Cliff Roth
Video Imaging DesignLine