SI5351A-B11981-GM1R

Clock Generators, PLLs, Frequency Synthesizers Overview

The SI5351A-B11981-GM1R is a factory preprogrammed I2C-configurable CMOS clock generator from Skyworks Solutions. It generates up to eight non-integer-related frequencies ranging from 2.5 kHz to 200 MHz with 0 ppm synthesis error. The device utilizes an internal oscillator and operates on a core supply voltage of 2.25 V to 3.6 V, while output buffers support 1.71 V to 3.6 V. It features low period jitter typically under 70 ps peak-to-peak and supports spread spectrum modulation. The component is housed in a 20-QFN package.

Clock Generators, PLLs, Frequency Synthesizers Feature Summary

• Generates multiple independent clock frequencies without integer relationships
• Eliminates the need for external crystals or oscillators via internal reference
• Provides glitchless frequency changes and configurable spread spectrum
• Supports static phase offset and adjustable output delay

Clock Generators, PLLs, Frequency Synthesizers Applications

• XO replacement in cost-sensitive designs
• Servers and storage systems
• Networking and communication equipment
• Residential gateways

Clock Generators, PLLs, Frequency Synthesizers Procurement Notes

Verify the specific factory preprogrammed configuration associated with the B11981 suffix against project requirements using ClockBuilder Pro software. Confirm that the 20-QFN package dimensions and thermal characteristics align with the target PCB layout constraints before finalizing procurement.

Clock Generators, PLLs, Frequency Synthesizers Selection Notes

Select this variant when a fixed, preconfigured clock solution is preferred over field-programmable units. Ensure the design does not require the VCXO functionality found in the Si5351B series or the external CLKIN synchronization of the Si5351C series. Validate that the required output count fits within the eight-output capacity of the 20-QFN package.

Clock Generators, PLLs, Frequency Synthesizers Part Context

This part belongs to the Si5351 family of programmable clock generators. The 'A' designation indicates it relies solely on an internal crystal oscillator rather than an external reference or VCXO. The 'GM1R' suffix denotes the 20-QFN package type and reel packaging format.

Clock Generators, PLLs, Frequency Synthesizers Replacement Considerations

Direct replacements include other Si5351A variants in the 20-QFN package, such as the blank-configuration SI5351A-B-GM1R, provided the existing firmware or hardware can handle I2C reprogramming.