High-speed repeater devices for digital video applications

September 28, 2007 -- TranSwitch has introduced its TransPHY- PXL repeater devices, designed to enable transmission of high bandwidth digital video over CAT-5 or HDMI copper cables.

September 28, 2007 -- TranSwitch has introduced its TransPHY- PXL repeater devices, designed to enable transmission of high bandwidth digital video over CAT-5 or HDMI copper cables.

According to the company, the chips extend Transition Minimized Differential Signaling (TMDS) channels for any digital visual interface (DVI) or high-definition multimedia interface (HDMI) digital video connection, and can increase the distance of DVI/HDMI signal transmission significantly over standard Cat 5 cable for flat panel displays, projectors, DVD players, set-top boxes and other audio/video sources.

"Although Cat 5 cable is not designed for use with high speed digital video signals, tests show that the TransPHY- PXL devices enable TMDS-encoded digital video signals to be sent and received on low cost Cat 5 cables, with longer distances possible over thicker cables like Cat 6 or Cat 7," says Amir Bar-Niv, executive director for systems and applications at TranSwitch Corp.

The company offers two TransPHY-PXL repeater devices, a single channel (TXC-42382) and dual channel (TXC-42384) version. The devices monitor the quality of the received signal using a proprietary Signal Quality Indicator (SQI) that optimizes the signal through a set of adjustable link parameters. This includes multiple pre-emphasis and amplitude levels on the transmit side, adjustable equalization on the receiver side, and impedance control on both sides, for each of the serial channels.

"The use of inexpensive Cat 5 cable for this application presents a number of technical challenges, such as signal skew, which is the time delay difference in each pair of wires causing the video signal components to become unaligned," continues Bar-Niv. "The TransPHY- PXL devices have a 'de-skew' feature which overcomes this problem by adding longer FIFOs that can de-skew higher delays between signals than the standard specifies."

The TransPHY- PXL devices are available now.


More in Home