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