General Description

The 843751 is a low jitter, high performance clock generator. The

843751 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 843751 has excellent (<1ps)

RMS phase jitter, over the SAS defined integration range. The

843751 uses an external, 25MHz, parallel resonant crystal to

generate 75MHz. This silicon based approach provides excellent

frequency stability and reliability. The 843751 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.

Features

• Designed for use in SAS, SAS-2 systems

• Up, down and center Spread Spectrum Clocking (SSC)

• One differential 3.3V or 2.5V LVPECL output pair

• Output frequency: 75MHz

• RMS phase jitter @ 75MHz, (900kHz – 7.5MHz):

0.734ps (typical) @ 3.3V

• 3.3V or 2.5V operating supply modes

• 0°C to 70°C ambient operating temperature

• Available in lead-free (RoHS 6) package

• Functional replacement part: 843002AYLF