SM802124UMG-TR

Clock Generators, PLLs, Frequency Synthesizers Overview

The SM802124UMG-TR is a ClockWorks™ dual 125MHz ultra-low jitter CMOS frequency synthesizer manufactured by Microchip Technology. It utilizes the patented RotaryWave architecture to generate two LVCMOS clock outputs at 125MHz from a single 15MHz LVCMOS reference input. The device operates within a supply voltage range of 2.375V to 3.465V and supports an industrial temperature range of –40°C to +85°C. Key electrical specifications include a typical RMS phase jitter of 85fs (1.875MHz–20MHz) and a PLL lock time of 20ms. It is housed in a 24-pin 4mm × 4mm QFN package with an exposed pad.

Clock Generators, PLLs, Frequency Synthesizers Feature Summary

• Generates two differential-capable LVCMOS clock outputs at 125MHz from a 15MHz reference
• Ultra-low phase noise: Typical RMS jitter of 85fs (1.875MHz–20MHz) and 320fs (12kHz–20MHz)
• RotaryWave architecture for extremely low-noise timing performance
• PLL bypass pin allows direct routing of the input reference clock to outputs

Clock Generators, PLLs, Frequency Synthesizers Applications

• Gigabit Ethernet systems requiring precise clocking
• Network infrastructure equipment
• High-speed data communication interfaces

Clock Generators, PLLs, Frequency Synthesizers Procurement Notes

Verify that the component matches the SM802124UMG-TR designation, which indicates the tape and reel shipping format. Confirm the manufacturer origin as Micrel/Microchip Technology. Ensure the package is the 24-pin QFN variant. Check compliance documentation for RoHS and PFOS status if required by specific manufacturing standards.

Clock Generators, PLLs, Frequency Synthesizers Selection Notes

Select this component when a low-jitter 125MHz dual output is required from a 15MHz source. The device requires a 15MHz LVCMOS input signal. Designers must account for a 20ms PLL lock time during power-up. The exposed pad on the QFN package must be soldered to the PCB ground plane to ensure proper thermal dissipation and electrical grounding.

Clock Generators, PLLs, Frequency Synthesizers Part Context

The SM802124 belongs to the ClockWorks family of devices originally developed by Micrel, Inc., which was acquired by Microchip Technology. The 'UMG' suffix denotes the 24-pin QFN package, while '-TR' specifies the tape and reel packaging option. This part is distinct from other SM802 variants based on its fixed 125MHz output frequency generation capability.

Clock Generators, PLLs, Frequency Synthesizers Replacement Considerations

The SM802124UMG (tube packaging) is functionally identical but differs in shipping format. No direct cross-model substitutes are documented in the provided datasheet.