GENERAL DESCRIPTION

The 843256I is a Crystal-to-3.3V LVPECL Clock Synthesizer/Fanout

Buffer designed for Fibre Channel and Gigabit Ethernet applications.

The output frequency can be set using the frequency select pins and

a 25MHz crystal for Ethernet frequencies, or a 19.44MHz crystal for

SONET. The low phase noise characteristics of the 843256I make

it an ideal clock for these demanding applications.

FEATURES

• Six 3.3V differential LVPECL output pairs

• Output frequency range: 62.5MHz to 625MHz

• Crystal input frequency range: 15.625MHz to 25.5MHz

• RMS phase jitter at 156.25MHz, using a 25MHz crystal

(1.875MHz to 20MHz): 0.41ps (typical) @ 3.3V

• Operating supply modes:

Core/Output

3.3V/3.3V

3.3V/2.5V

• -40°C to 85°C ambient operating temperature

• Available in lead-free (RoHS 6) package