Integrated Device Technology FemtoClock SAS/SATA Clock Generator 843241BM-300LF

The 843241 is a low jitter, high performance clock generator and a member of the FemtoClock® family of silicon timing products. The 843241 is designed for use in the SAS -2 interconnect and the three transport protocols that use the SAS -2 interconnect: Serial SCSI Protocol ( SSP ), Serial ATA Tunneled Protocol ( STP ), and Serial Management Protocol ( SMP ). The 843241 has excellent (<1ps) RMS phase jitter, over the SAS defined integration range. The 843241 uses an external, 25MHz, parallel resonant crystal to generate three selectable output frequencies: 75MHz, 100MHz, 150MHz, and 300MHz. This silicon based approach provides excellent frequency stability and reliability. The 843241 features up, down, and center spread spectrum ( SSC ) clocking techniques. The up, down and center SSC will be required in the SAS -2 applications that have three clock trees in the HBA and expander ASICs (see Applications Information section, Figure 3).