Vitesse Semiconductor Corporation expanded its crosspoint switch family with the introduction of the industry's lowest power 36x36 and 68x68 crosspoint switches. Building on its expertise in the SONET/SDH arena, Vitesse designed Integrated Signal Equalization (ISE) capability into its crosspoint switches to eliminate the effects of Inter-Symbol Interference (ISI) that can occur in applications that use long, narrow PCB traces to route the incoming signal, such as Clos switch fabrics used in Digital Cross-connect Systems (DCS).

The VSC837 and VSC838 incorporate novel, proprietary functionality called Integrated Signal Equalization (ISE) on every input to the switching matrix. This ýjitter eating' capability results in less output jitter when the incoming jitter is deterministic in nature. By reducing jitter, ISE facilitates the development of large three or five stage Clos switch fabrics by improving the multi-pass performance of the switch and eliminating the need for inter stage retimers, thereby reducing the overall system cost. To further enhance system level application, the VSC837 and VSC838 provide Input Signal Activity (ISA) monitoring to provide in-system diagnostics. Both switch matrices offer fully non-blocking operation with broadcast and multicast capabilities. The VSC837 68x68 a 3.2Gb/s crosspoint switch, and the VSC838 a 36x36 3.2Gb/s crosspoint switch are ideal for designers of high speed applications such as SONET/SDH Dense Wavelength Division Multiplexing (DWDM), SAN switches, HDTV/SDTV Serial Routing, Production, and Master Control Switchers, and Automatic Test Equipment (ATE).

The VSC837 and VSC838 provide the industry's lowest power dissipation, i.e., typical power dissipation for the VSC838 and the VSC837 is 6W and 11W, respectively. In addition, these devices integrate software and hardware power down capabilities to disable unused input and output channels. Both devices feature programmable output amplitude and have on-chip 50 Ohm back terminations that can be enabled or disabled to further reduce power consumption.

The VSC837 provides a multi-mode programming interface that allows programming commands to be sent as serial data, parallel data or BURST mode data. The VSC838's multi-mode programming interface allows programming commands to be sent as serial or parallel data. The high speed serial inputs are internally biased and provide on-die 100 Ohm line-to-line terminations for improved signal integrity and reduced PCB space requirements.

The VSC837 is a crosspoint based on a multiplexer array with each output driven from a 68:1 multiplexer that can be programmed to only one of the inputs at a time. All the channels are fully independent so that the signals at each output can be totally independent in frequency, phasing and nature. The outputs have switchable on-die terminations while the inputs are all terminated on die. The data bandwidth through the part can be up to 3.2 Gbit/s NRZ. A 69th output is provided to drive an activity monitor to allow for in-system diagnostics.

A triple-mode programming interface (at 66 MHz) allows commands to be delivered either on a serial or parallel data bus; the preferred mode -- burst -- allows for an input to be routed to all outputs in 4 program cycles. Programming can be random or assignments can be queued and activated simultaneously with three areas of control: The core program registers are independent of the program memory, which itself is independent of the program interface.

Vitesse is applying a new technology to the inputs which it is calling Integrated Signal Equalization (ISE) and it is said to reduce the ISI jitter on the input. The part is a 2.5-V product with a 16 W maximum consumption. There are hard and soft powerdown modes for channels that are not in use.

Both the VSC837 and the smaller VSC838 are in production in 37.5 x 37.5 mm TBGA-480. The VSC837 is priced at $769 and the VSC838 is priced at $325, both for 1000-piece lots.

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