Crosspoint switch

National Semiconductor has introduced a 1.5 Gbps 2×2 Low Voltage Differential Signalling analogue crosspoint switch with programmable pre-emphasis and IEEE 1149.6 testability.

National Semiconductor has introduced a 1.5 Gbps 2×2 Low Voltage Differential Signalling (LVDS) analogue crosspoint switch with programmable pre-emphasis and IEEE 1149.6 testability.

The SCAN90CP02’s pre-emphasis feature boosts the signal for improved data integrity across lossy backplanes and cables, while the IEEE 1149.6 circuitry supports a new standard to test these backplanes and cables.

National’s device is a two-input, two-output LVDS non-blocking crosspoint switch that is capable of many different configurations, including a conventional crosspoint switch, a buffer/repeater, a 1:2 splitter, and a 2:1 multiplexer.

Crosspoint switches are commonly used as a splitter or mux function in networking and communications infrastructure equipment to provide redundancy for data and clock signals.

‘While other LVDS buffers and switches only minimise the jitter they add to the system, the SCAN90CP02 can actually remove jitter, increasing system reliability and allowing the use of a less expensive interconnect,’ said Thomas Wirschem, marketing manager PC and Networking Group, Europe.

‘With pre-emphasis, the SCAN90CP02 can be used not only for normal switching but also as a buffer to boost existing FPGA, ASIC and SerDes LVDS signals.’

IEEE1149.6 is a recently approved specification for evaluating previously untestable AC-coupled interconnects. Support for 1149.6 is important because many high-speed LVDS connections now use AC-coupling (capacitive coupling) to eliminate signal offsets between drivers and receivers that reside at remote locations.

The SCAN90CP02 testability features include IEEE 1149.1 (JTAG), IEEE 1149.6, and a supplementary IEEE 1149.1-initiated fault insertion capability to verify system level fail-over and redundancy modes. These features lower test time, and reduce test and development costs.

Learn more about LVDS by clicking <a href=’http://www.national.com/analogu/lvds/101/lesson1.html’>here</a>.