GENERAL DESCRIPTION
The 844001 is a Fibre Channel Clock Generator. The 844001 uses an
18pF parallel resonant crystal over the range of 20.4MHz - 28.3MHz.
For Fibre Channel applications, a 26.5625MHz crystal is used. The
frequency select pin allows the device to generate either 106.25MHz
or 212.5MHz from a 26.5625MHz crystal. To generate 187.5MHz for
12Gb Ethernet, a 23.4375MHz crystal is used. The 844001 uses IDT’s
3rd generation low phase noise VCO technology and can achieve
<1ps typical rms phase jitter, easily meeting Fibre Channel and
Ethernet jitter requirements. The 844001 is packaged in a small 8-pin
TSSOP, making it ideal for use in systems with limited board space.
NOTE: It is not recommended to overdrive the crystal input with an
external clock.

FEATURES
• One Differential LVDS output
• Crystal oscillator interface, 18pF parallel resonant crystal
(20.4MHz - 28.3MHz)
• Output frequency range: 81.66MHz - 226.66MHz
• VCO range: 490MHz - 680MHz
• RMS phase jitter @ 106.25MHz, using a 26.5625MHz crystal
(637kHz - 10MHz): 0.74ps (typical)
• 3.3V or 2.5V operating supply
• 0°C to 70°C ambient operating temperature
• Available in lead-free (RoHS 6) package
• For functional replacement part use 8T49N242