General Description

The 843242 is a two differential output LVPECL 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 4

frequency select pins (SELA[1:0], SELB[1:0]): 625MHz, 312.5MHz,

156.25MHz, and 125MHz.

The two banks have their own dedicated frequency select pins and

can be independently set for the frequencies mentioned above. The

843242 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 843242 is packaged in a small

16-pin TSSOP package.

Features

• Two differential LVPECL 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

• Crystal oscillator interface

• RMS Phase Jitter @ 625MHz, (1.875MHz – 20MHz) using a

25MHz crystal: 0.4ps (typical)

• Full 3.3V supply mode

• 0°C to 70°C ambient operating temperature

• Lead-free (RoHS 6) packaging