Overview
Description
The 843252 is a 2 differential output LVPECL synthesizer designed to generate Ethernet reference clock frequencies. Using a 25MHz, 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 843252 uses our 3rd generation low phase noise VCO technology and can achieve 1ps or lower typical rms phase jitter, easily meeting Ethernet jitter requirements. The 843252 is packaged in a small 16-pin TSSOP package.
Features
- Two differential LVPECL output pairs
- Using a 25MHz crystal, the two output banks can be independently set for 625MHz, 312.5MHz, 156.25MHz or 125MHz
- Crystal oscillator interface
- VCO frequency: 490MHz – 680MHz
- RMS Phase Jitter @ 156.25MHz, (1.875MHz – 20MHz) using a 25MHz crystal: 0.47ps (typical)
- Full 3.3V supply mode
- 0°C to 70°C ambient operating temperature
- Industrial temperature available upon request
- Available in lead-free (RoHS 6) package
Comparison
Applications
Design & Development
Models
ECAD Models
Schematic symbols, PCB footprints, and 3D CAD models from SamacSys can be found by clicking on the CAD Model links in the Product Options table. If a symbol or model isn't available, it can be requested directly from SamacSys.

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