SM802120UMG

Clock Generators, PLLs, Frequency Synthesizers Overview

The SM802120UMG is a ClockWorks frequency synthesizer utilizing patented RotaryWave architecture for ultra-low jitter performance. It generates eight 125MHz differential outputs: six LVDS and two HCSL. The device accepts a 25MHz crystal input and operates from a 3.3V or 2.5V power supply. Typical RMS phase jitter is 100fs (1.875MHz to 20MHz) and 250fs (12KHz to 20MHz). It functions within an industrial temperature range of –40°C to +85°C and is housed in a 44-pin 7mm x 7mm QFN package.

Clock Generators, PLLs, Frequency Synthesizers Feature Summary

• Generates six LVDS and two HCSL 125MHz clocks
• Typical phase jitter of 100fs at 125MHz (1.875MHz to 20MHz)
• Operates on 2.5V or 3.3V power supplies
• Industrial temperature range (-40°C to +85°C)

Clock Generators, PLLs, Frequency Synthesizers Applications

• CPRI interfaces
• OBSAI systems
• GbE applications

Clock Generators, PLLs, Frequency Synthesizers Procurement Notes

Verify the manufacturer origin, as the datasheet identifies Micrel, Inc., while the model number prefix suggests Microchip Technology acquisition. Confirm RoHS compliance status and check current availability through authorized distributors, as this component may be subject to lifecycle changes or obsolescence.

Clock Generators, PLLs, Frequency Synthesizers Selection Notes

Select the SM802120UMG when low jitter timing is required for 125MHz clock distribution. Ensure the design supports both LVDS and HCSL termination requirements. Verify that the system can accommodate the specific 25MHz crystal reference input without external load capacitors.

Clock Generators, PLLs, Frequency Synthesizers Part Context

This component belongs to the ClockWorks family of precision synthesizers. It was originally manufactured by Micrel, Inc., which was acquired by Microchip Technology. The part utilizes unique RotaryWave architecture to achieve superior phase noise characteristics compared to standard PLL-based synthesizers.

Clock Generators, PLLs, Frequency Synthesizers Replacement Considerations

SM802120UMGTR is the tape and reel version of the same functional device. No direct cross-manufacturer substitutes are confirmed in the provided documentation.

Clock Generators, PLLs, Frequency Synthesizers FAQ

Does the SM802120 require external load capacitors for the crystal input?

No, the internal die includes built-in crystal load capacitance, so no external capacitors are needed.

How should the LVDS outputs be terminated?

LVDS outputs must be terminated with a 100Ω resistor across the Q and /Q pins.

What is the integration range for the typical 100fs jitter specification?

The 100fs typical phase jitter is measured over an integration range of 1.875MHz to 20MHz.