SI5351B-B11982-GM1R

Clock Generators, PLLs, Frequency Synthesizers Overview

The SI5351B-B11982-GM1R is an I2C-programmable CMOS clock generator featuring a VCXO reference and eight LVCMOS outputs. It operates on a PLL/VCXO architecture with MultiSynth fractional dividers to generate any frequency up to 200 MHz with 0 ppm error. The device accepts a 25 or 27 MHz crystal input and supports configurable spread spectrum, static phase offsets, and glitchless frequency changes. It functions within a core supply voltage range of 2.25 V to 3.6 V and output buffer voltages of 1.71 V to 3.6 V. The component is housed in a QFN-16 package and operates across a temperature range of -40 °C to +85 °C.

Clock Generators, PLLs, Frequency Synthesizers Feature Summary

• Integrates an internal VCXO for synchronous clock generation without requiring custom pullable crystals.
• Generates up to eight non-integer-related frequencies from 2.5 kHz to 200 MHz using high-resolution MultiSynth dividers.
• Supports I2C user-definable configuration for exact frequency synthesis at each output.
• Provides separate voltage supply pins for level translation between core logic and output buffers.

Clock Generators, PLLs, Frequency Synthesizers Applications

• Replacing crystals, crystal oscillators, VCXOs, and PLLs in cost-sensitive designs.
• Networking and communication equipment requiring precise clock domains.
• Servers and storage systems needing multiple asynchronous clock sources.
• Residential gateways and handheld instrumentation.

Clock Generators, PLLs, Frequency Synthesizers Procurement Notes

Verify the factory preprogrammed configuration code '11982' matches the required clock frequencies before integration. Confirm that the GM1R suffix indicates tape-and-reel packaging suitable for automated assembly processes. Ensure the specific silicon revision aligns with the design requirements for jitter performance and power consumption characteristics.

Clock Generators, PLLs, Frequency Synthesizers Selection Notes

Select this model when both free-running and synchronous clocks are required from a single device. The Si5351B variant is necessary if VCXO functionality is needed for applications requiring frequency pulling. Compare against Si5351A if only XTAL-based free-running clocks are sufficient, or Si5351C if external CLKIN synchronization is preferred over internal VCXO control.

Clock Generators, PLLs, Frequency Synthesizers Part Context

This part belongs to the Si5351 family of programmable clock generators. The 'B' designation specifically denotes the inclusion of an internal Voltage-Controlled Crystal Oscillator (VCXO). The 'GM1R' suffix identifies the 16-QFN package type containing four outputs and tape-and-reel packaging. This distinguishes it from the 20-QFN version which provides eight outputs.

Clock Generators, PLLs, Frequency Synthesizers Replacement Considerations

SI5351B-B-GM1R