SMALL CDR OPTIMIZED FOR SWITCH APPLICATIONS
Editor: The MAX3873 is a significant new product. It is the lowest power 2.5Gbps CDR with high jitter tolerance optimized for switch core applications.SUNNYVALE, CA-August 15, 2001-Maxim Integrated introduces the MAX3873, a small, low-power 2.488/2.67Gbps clock recovery and data retiming IC (CDR) for SDH/SONET switch matrix, receiver/regenerator, and DWDM applications. The MAX3873 offers industry-leading features and performance with minimal impact on board area and power budgets. Fast acquisition times (1.0ms), high jitter tolerance (0.7UIp-p at 1MHz), and a wide input-voltage range (50mVp-p to 1600mVp-p) enable high-speed signal routing in switch-core and backplane applications. Implemented in Maxims second generation SiGe process, the MAX3873 consumes only 260mW at +3.3V supply (output clock disabled, low output swing) in a 4mm x 4mm footprint.
The 2.488Gbps or 2.67Gbps selectable phase-locked loop (PLL) recovers a synchronous clock signal from the serial NRZ data input. The input data is then retimed by this recovered clock, providing a clean data output. Its jitter generation (5mUIRMS) performance exceeds the SDH/SONET specifications. The MAX3873 does not require an external reference clock for frequency acquisition and provides excellent tolerance to both deterministic and sinusoidal jitter: 0.3UIp-p jitter tolerance at 10MHz with 0.4UIp-p deterministic jitter at the input.
The MAX3873 provides a PLL loss-of-lock LOL-bar output to indicate whether the CDR is locked to the incoming data stream. The recovered clock and data outputs are differential CML with on-chip 50Ω back terminations on each line, and have selectable output amplitudes. The clock output can be powered down if it is not used.
The MAX3873 is available in a 4mm x 4mm 20-pin QFN package with exposed pad and operates from a 3.3V supply over a temperature range of -40°C to +85°C. The MAX3873 is priced at $19.95 (1000-up, factory direct). Evaluation kits are available.