SI5381A-D-GMR

Clock Generators, PLLs, Frequency Synthesizers Overview

The Si5381A-D-GMR is a multi-DSPLL wireless jitter attenuator and clock multiplier from Skyworks Solutions. It integrates four digital silicon phase-locked loops (DSPLLs) in a single chip, replacing discrete VCXO-based solutions. The device supports simultaneous Ethernet, CPRI, and general-purpose clocking with ultra-low noise performance. It features 4 differential inputs and 12 outputs within a 64-lead QFN package. Maximum output frequencies reach 2.94912 GHz for CPRI clocks via DSPLL_B and 735 MHz for other differential outputs. Input frequency ranges are 8 kHz to 750 MHz for differential signals and 8 kHz to 250 MHz for LVCMOS. Core voltage is 1.8 V ±5%, with independent output supplies of 3.3 V, 2.5 V, or 1.8 V.

Clock Generators, PLLs, Frequency Synthesizers Feature Summary

• Integrates four digital silicon phase-locked loops (DSPLLs) to eliminate external VCXOs and analog loop filters
• Supports simultaneous generation of Ethernet, CPRI, and general-purpose clocks with hitless input switching
• Provides automatic free-run and holdover modes using non-volatile memory for frequency stability
• Features programmable loop bandwidths and Fastlock capability for rapid lock acquisition

Clock Generators, PLLs, Frequency Synthesizers Applications

• Wireless Infrastructure Baseband Units (BBU)
• Distribution Units (DU) in cellular networks
• eCPRI Remote Radio Heads (RRH)
• Test and Measurement equipment requiring low-jitter timing

Clock Generators, PLLs, Frequency Synthesizers Procurement Notes

Verify the specific ordering suffix against the manufacturer's current datasheet revision. Confirm that the 'D' designation aligns with the required pinout and configuration options for the target application. Ensure compatibility with the 64-QFN package land pattern during PCB design review.

Clock Generators, PLLs, Frequency Synthesizers Selection Notes

Select this component when a single-chip solution is needed to replace multiple discrete jitter attenuators. Verify that the required output frequencies fall within the 2.94912 GHz CPRI limit or 735 MHz general-purpose limit. Check if the four-input architecture meets the system's redundancy and switching requirements.

Clock Generators, PLLs, Frequency Synthesizers Part Context

This part belongs to the Si538x family of multi-DSPLL wireless jitter attenuators. It is designed to provide a clock-tree-on-a-chip solution for applications requiring mixed clock frequencies. The device utilizes 4th generation DSPLL technology to deliver superior immunity to external board disturbances such as power supply noise.

Clock Generators, PLLs, Frequency Synthesizers Replacement Considerations

Direct replacement parts include SI5381A-E-GM and SI5381E-E-GMR. Verify functional equivalence regarding DSPLL count and output configurations before substitution.