SI5351B-B04778-GMR

Clock Generators, PLLs, Frequency Synthesizers Overview

The SI5351B-B04778-GMR is an I2C-programmable CMOS clock generator featuring an integrated VCXO. It generates up to eight non-integer-related frequencies from 2.5 kHz to 200 MHz with 0 ppm error. The device operates on a core supply of 2.5 V or 3.3 V and output supplies of 1.8, 2.5, or 3.3 V. It utilizes a 20-QFN package and accepts a 25 or 27 MHz crystal reference. Key electrical parameters include a typical period jitter of 70 ps pp and a maximum operating temperature of +85 °C.

Clock Generators, PLLs, Frequency Synthesizers Feature Summary

• Integrates a highly linear VCXO for synchronous clock generation without external pullable crystals
• Generates multiple independent frequencies using MultiSynth fractional dividers
• Supports configurable spread spectrum modulation at each output
• Provides separate voltage supply pins for level translation between core and outputs

Clock Generators, PLLs, Frequency Synthesizers Applications

• Replacing crystals, crystal oscillators, and VCXOs in cost-sensitive designs
• Networking and communication equipment requiring precise timing
• Servers and storage systems needing glitchless frequency changes
• Printers, scanners, and projectors utilizing programmable clocks

Clock Generators, PLLs, Frequency Synthesizers Procurement Notes

Verify the factory preprogrammed configuration code B04778 matches the required frequency plan before integration. Confirm the GMR suffix indicates tape and reel packaging suitable for automated assembly. Ensure the design supports the specific I2C address and register map defined by Skyworks Solutions for this variant.

Clock Generators, PLLs, Frequency Synthesizers Selection Notes

Select this model when both free-running and synchronous clock domains are required within a single component. The Si5351B variant is necessary if VCXO functionality is needed to replace custom pullable crystals. Verify that the 20-QFN package dimensions fit the PCB layout constraints compared to the 16-QFN or 10-MSOP options.

Clock Generators, PLLs, Frequency Synthesizers Part Context

This part belongs to the Si5351A/B/C-B family of programmable clock generators. The 'B' designation specifically denotes the inclusion of an internal Voltage Controlled Crystal Oscillator (VCXO), distinguishing it from the Si5351A which lacks this feature. The 'GMR' suffix typically indicates a reel-based packaging format for surface-mount technology.

Clock Generators, PLLs, Frequency Synthesizers Replacement Considerations

SI5351B-B-GM serves as the blank version of this component family.