VSC1238

The VSC1237 and VSC1238 is a complete highperformance multiplexer/demultiplexer chip set designed for 9.9-12.5 Gbps applications, including SONET OC-192, SDH STM-64, 10GbE, G.975, G.709 and offering enhanced capabilities specifically designed to address the needs of Ultra Long Haul (ULH) and Long Haul (LH) fiber optic transmission systems.

The VSC1237 is a 16:1 Multiplexer with an integrated Clock Multiplier Unit. This device easily surpasses the jitter requirements for SONET/SDH transmission systems. Integrated phase locked loop circuits, including VCOs, are used for high speed clock generation, jitter filtering and low-speed data transfer. This device offers enhanced features, such as a integrated jitter filter PLL and a selectable full/half-rate clock output, which is specifically designed to be used in long haul and ultra long haul systems that utilize clocked laser drivers or RZ signaling. The clock output features extremely low clock-data skew variation, and can be disabled to save power.

The VSC1238 is a 1:16 Demultiplexer (DMUX) with Clock and Data Recovery (CDR) unit. This device is capable of direct recovery of signals which are subject to various impairments/formats inherent in ULH/LH systems, including poor Optical Signal to Noise Ratio (OSNR) arising from optical amplification, distortion from Chromatic Dispersion, Polarization Mode Dispersion / Differential Group Delay (PMD/DGD), and RZ signaling. The highly sensitive front-end, precise phase detector / decision circuit, and adaptive threshold features eliminate the need for AGC amplifiers, post-amplifiers, filters, etc. which are traditionally needed to recover these signals.