General Description

The 844003 is a three differential output LVDS Synthesizer designed

to generate Ethernet reference clock frequencies. Using a 31.25MHz

or 26.041666MHz, 18pF parallel resonant crystal, the following

frequencies can be generated based on the settings of four

frequency select pins (DIV_SEL[A1:A0], DIV_SEL[B1:B0]): 625MHz,

312.5MHz, 156.25MHz, and 125MHz. The 844003 has two output

banks, Bank A with one differential LVDS output pair and

Bank B with two differential LVDS output pairs.

The two banks have their own dedicated frequency select pins and

can be independently set for the frequencies mentioned above. The

844003 uses IDT’s 3rd generation low phase noise VCO technology

and can achieve 1ps or lower typical rms phase jitter, easily meeting

Ethernet jitter requirements. The 844003 is packaged in a small

24-pin TSSOP package.

Features

• Three LVDS outputs on two banks, A Bank with one LVDS pair

and B Bank with two LVDS output pairs

• Using a 31.25MHz or 26.041666MHz crystal, the two output

banks can be independently set for 625MHz, 312.5MHz,

156.25MHz or 125MHz

• Selectable crystal oscillator interface or LVCMOS/LVTTL

single-ended input

• VCO range: 560MHz to 700MHz

• RMS phase jitter @ 156.25MHz (1.875MHz - 20MHz): 0.63ps (typical)

• 3.3V output supply mode

• 0°C to 70°C ambient operating temperature

• Available in lead-free (RoHS 6) packaging