Clock distribution

Texas Instruments has introduced a number of multipoint-LVDS (M-LVDS) line drivers for clock distribution, providing high performance for heavily-loaded backplanes.

Compliant with the M-LVDS specification TIA/EIA-899, the devices provide a drive current of 11.3 mA with edge rate control and are suitable for a range of high-speed, inter- and intra-system communications, including wireless base station backplanes, AdvancedTCA (Advanced Telecom Computing Architecture) clock buses, network switches and routers.

The SN65MLVD128 and SN65MLVD129 offer a space and cost-saving alternative to typical methods that involve two separate devices for fanout and LVTTL to differential signal conversion. In addition, the higher output levels and lower input thresholds of M-LVDS provide more than twice the noise margin of typical LVDS-compliant devices.

The MLVD128 and MLVD129 are 30-ohm to 50-ohm line drivers providing low-voltage differential signalling for clock frequencies up to 125 MHz. The MLVD128 1:8 fanout buffer and MLVD129 dual 1:4 device provide solutions for repeating a single-ended source clock differentially with low power and low electromagnetic interference (EMI). The MLVD047 is a quadruple M-LVDS line driver for 30-ohm to 55-ohm loads and data rates up to 200 Mbps or clock frequencies up to 100 MHz.

M-LVDS is the only LVDS standard for use on buses that provides the edge rates, drive strength, thresholds and contention provisions that enable the flexible distributed clock distribution scheme specified by the AdvancedTCA specification of the PCI Industrial Computer Manufacturers Group. The MLVD128/129/047 devices can distribute clocks on network equipment that is compliant to AdvancedTCA.

The MLVD128 and MLVD129 are packaged in 48-pin thin shrink small outline package (TSSOP), and the SN65MLVD047 is available in 16-pin small outline integrated circuit (SOIC) or 16-pin TSSOP.

Suggested resale pricing in 1,000-piece quantities is $3.80 each for the MLVD128 and MLVD129 and $1.45 each for the MLVD047.

On the web