General Description
The 840004-01 is a 4 output LVCMOS/LVTTL Synthesizer
optimized to generate Ethernet reference clock frequencies. Using
a 25MHz, 18pF parallel resonant crystal, the following frequencies
can be generated based on the 2 frequency select pins
(F_SEL1:0): 156.25MHz, 125MHz, and 62.5MHz. The 840004-01
uses IDT’s 3rd generation low phase noise VCO technology and
can achieve 1ps or lower typical random rms phase jitter, easily
meeting Ethernet jitter requirements. The 840004-01 is packaged
in a small 20-pin TSSOP package.

Features
• Four single-ended LVCMOS/LVTTL outputs
17 typical output impedance
• Selectable crystal oscillator interface or single-ended input
• Output frequency range: 56MHz - 175MHz
• VCO range: 560MHz - 700MHz
• RMS phase jitter at 156.25MHz (1.875MHz – 20MHz):
0.52ps (typical)
Phase Noise:
Offset Noise Power
100Hz -94.9 dBc/Hz
1kHz -119.6 dBc/Hz
10kHz -128.9 dBc/Hz
100kHz -129.2 dBc/Hz
• Full 3.3V or mixed 3.3V core/2.5V output supply modes
• 0°C to 70°C ambient operating temperature
• Available in lead-free (RoHS 6) package