1. Overview
In addition to clock generation, the inputs can bypass the synthesis stage enabling the Si5357 to be used as a high-performance clock
buffer or a combination of a buffer and generator. For applications that need fine frequency adjustments, such as clock margining,
outputs from the MultiSynth bank can be incremented or decremented by at least ±50 ppm in user-defined steps as low as 10-20 ppb
per step. This can be done through ID frequency select feature. Spread spectrum is available for any clock output from two Multisynth
dividers for use in EMI-sensitive applications, such as PCI Express. Configurations and controls of the Si5357 are mainly handled
through I2C. Any GPI pin can be programmed to be clock input select, frequency select, spread enable, output enable, resetb, and I2C
address select.
To enable in-system programming, a power up mode is available through OTP which powers up the chip in an OTP defined default
mode but with no outputs enabled. This allows a microcontroller to first write a user defined subset of the registers and then restart the
power-up sequence to activate the newly programmed configuration without re-downloading the OTP.
Si5357 Reference Manual • Overview
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com
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Rev. 0.2 • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice • July 26, 2021
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