SI5351B-B04745-GM

Clock Generators, PLLs, Frequency Synthesizers Overview

The SI5351B-B04745-GM is a factory preprogrammed I2C programmable clock generator from Skyworks Solutions. It features an integrated VCXO and generates up to eight independent non-integer-related frequencies ranging from 2.5 kHz to 200 MHz with 0 ppm synthesis error. The device operates on a core supply voltage of 2.5 V or 3.3 V and output voltages of 1.8, 2.5, or 3.3 V. It utilizes a MultiSynth fractional divider architecture and accepts a standard 25 MHz or 27 MHz crystal reference. The component is housed in a 20-QFN package.

Clock Generators, PLLs, Frequency Synthesizers Feature Summary

• Integrates a highly linear VCXO to eliminate the need for custom pullable crystals
• Generates multiple synchronous and free-running clocks using dual PLLs and MultiSynth dividers
• Supports configurable spread spectrum modulation at each individual output
• Provides glitchless frequency changes and static phase offset capabilities

Clock Generators, PLLs, Frequency Synthesizers Applications

• Replacing crystals, crystal oscillators, and VCXOs in cost-sensitive designs
• Audio and video equipment requiring precise clock synchronization
• Networking and communication systems needing low jitter generation
• Servers and storage devices utilizing PCIE Gen 1 compatible signals

Clock Generators, PLLs, Frequency Synthesizers Procurement Notes

Verify the specific factory preprogrammed configuration associated with the B04745 suffix using ClockBuilder Pro software before integration. Confirm that the required output frequencies and reference crystal specifications match the internal memory settings. Ensure the design supports the I2C interface for any necessary runtime updates if the part allows RAM access.

Clock Generators, PLLs, Frequency Synthesizers Selection Notes

Select this variant when a fixed, factory-defined clock configuration is preferred over user-programmable flexibility. The Si5351B series specifically requires an external crystal but includes the VCXO functionality for tuning applications. Verify that the target application does not require an external CLKIN reference, which is reserved for the Si5351C series.

Clock Generators, PLLs, Frequency Synthesizers Part Context

This component belongs to the Si5351A/B/C-B family of CMOS clock generators. The 'B' designation indicates the inclusion of an internal Voltage Controlled Crystal Oscillator (VCXO). The 'GM' suffix denotes the 20-QFN package type. This family replaces discrete timing components like XO, VCXO, and PLLs with a single programmable IC.

Clock Generators, PLLs, Frequency Synthesizers Replacement Considerations

SI5351B-B-GM

Clock Generators, PLLs, Frequency Synthesizers FAQ

What is the maximum output frequency supported by this device?

The device can generate output frequencies up to 200 MHz.

How many outputs are available in the 20-QFN package?

The 20-QFN package provides eight independent clock outputs.

Does this part support spread spectrum modulation?

Yes, spread spectrum modulation is selectable at each output.