General Description
The ICS845204 is a 4 output PCI Express clock
synthesizer optimized to generate low jitter PCI
Express™ reference clocks with or without spread
spectrum modulation and is a member of the
HiPerClockS™ family of high performance clock
solutions from IDT. Spread type and amount can be configured via
the SSC control pins. Using a 25MHz, 18pF parallel resonant
crystal, the device will generate M-LVDS clocks at either 25MHz,
100MHz, 125MHz or 250MHz. The ICS845204 uses a low jitter
VCO that easily meets PCI Express jitter requirements and is
packaged in a 32-pin VFQFN package.
Features
• Four differential spread spectrum clock outputs
• Each output can be individually disabled by separate
output-enable inputs
• Crystal oscillator interface designed for 18pF,
25MHz parallel resonant crystal
• Supports the following output frequencies:
25MHz, 100MHz, 125MHz or 250MHz
• VCO range: 250MHz - 700MHz
• Supports SSC downspread at 0.05% and -0.75%, centerspread
at ±0.25% and no spread options
• Cycle-to-cycle jitter: 50ps (maximum) design target
• Period jitter, RMS: TBD
• Full 3.3V output supply mode
• 0°C to 70°C ambient operating temperature
• Available in both standard (RoHS 5) and lead-free (RoHS 6)
packages