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