Si5381/82 Rev E Data Sheet Multi-DSPLL Wireless Jitter Attenuator / Clock Multiplier with KEY FEATURES Ultra-Low Noise Supports simultaneous Ethernet, CPRI and The Si5381/82 is an ultra high performance wireless jitter attenuator with multiple general-purpose clocking in a single device DSPLLs, optimized for wireless BBU (Baseband Unit) and DU (Distribution Unit) ap- Input frequency range: plications. The industrys first multi-PLL wireless jitter attenuator device is capable of Differential: 8 kHz - 750 MHz replacing multiple discrete, high performance, VCXO-based jitter attenuators with a LVCMOS: 8 kHz to 250 MHz fully integrated single chip solution. The featured multi-PLL architecture supports tim- ing paths for Ethernet and CPRI (Common Public Radio Interface) clock cleaning , Output frequency range: and generates any low-jitter, general-purpose clocks. The fixed frequency oscillator CPRI: up to 2.94912 GHz provides frequency stability for free-run and holdover modes. This all-digital solution Other differential: up to 735 MHz provides superior performance that is highly immune to external board disturbances LVCMOS: up to 250 MHz such as power supply noise. Ultra-low RMS jitter: 72 fs typ (12 kHz20 MHz) Applications: Phase noise of 122.88MHz carrier frequency: Wireless Infrastructure -118 dBc/Hz 100Hz offset ITU-T G.8262 compliant eCPRI RRH (Remote Radio Head) BBU (Baseband Unit) DU (Distribution Unit) Test and Measurement 54 MHz OSC N R OUT0A IN SEL N R OUT0 DSPLL IN0 P B R OUT1 N 14.7456 GHz PLL IN1 P N R OUT2 DSPLL R OUT3 IN2 P A Si5382 R OUT4 DSPLL IN3 P C R OUT5 DSPLL R OUT6 D Any-Rate PLLs R OUT7 Si5381 NVM R OUT8 2 Control I C/SPI R OUT9 Status Flags Status R OUT9A Skyworks Solutions, Inc. Phone 781 376-3000 Fax 781 376-3100 sales skyworksinc.com www.skyworksinc.com 1 Rev. 1.0 Skyworks Proprietary Information Products and Product Information are Subject to Change Without Notice December 3, 2021 1Table of Contents 1. Features List ...............................4 2. Ordering Guide ..............................5 3. Functional Description............................6 3.1 Frequency Configuration ..........................6 3.1.1 Si5381/82 CPRI Frequency Configuration ...................6 3.1.2 Si5381/82 Configuration for Wireless Clock Generation...............7 3.2 DSPLL Loop Bandwidth...........................8 3.3 Fastlock Feature .............................8 3.4 Modes of Operation ............................8 3.4.1 Initialization and Reset..........................8 3.4.2 Freerun Mode.............................9 3.4.3 Lock Acquisition Mode..........................9 3.4.4 Locked Mode.............................9 3.4.5 Holdover Mode ............................9 3.4.6 VCO Freeze Mode ...........................10 3.5 External Reference (XA/XB) .........................10 3.6 Inputs (IN0, IN1, IN2, IN3) ..........................11 3.6.1 Manual Input Switching (IN0, IN1, IN2, IN3)...................11 3.6.2 Automatic Input Selection (IN0, IN1, IN2, IN3)..................12 3.6.3 Hitless Input Switching..........................12 3.6.4 Ramped Input Switching .........................12 3.6.5 Glitchless Input Switching.........................12 3.7 Fault Monitoring .............................13 3.7.1 Input LOS Detection...........................13 3.7.2 Reference Clock LOS Detection.......................13 3.7.3 OOF Detection ............................14 3.7.4 LOL Detection.............................15 3.7.5 Interrupt Pin (INTRb) ..........................17 3.8 Outputs ................................17 3.8.1 Output Crosspoint ...........................18 3.8.2 Output Signal Format ..........................18 3.8.3 Output Terminations...........................19 3.8.4 Programmable Common Mode Voltage For Differential Outputs............19 3.8.5 LVCMOS Output Impedance and Drive Strength Selection..............20 3.8.6 LVCMOS Output Signal Swing .......................20 3.8.7 LVCMOS Output Polarity.........................20 3.8.8 Output Enable/Disable..........................20 3.8.9 Output Disable During LOL ........................20 3.8.10 Output Disable During Reference LOS....................20 3.8.11 Output Driver State When Disabled .....................20 3.8.12 Synchronous Output Disable Feature ....................21 3.8.13 Static Output Skew Control ........................21 3.8.14 Dynamic Output Skew Control.......................21 Skyworks Solutions, Inc. Phone 781 376-3000 Fax 781 376-3100 sales skyworksinc.com www.skyworksinc.com 2 Rev. 1.0 Skyworks Proprietary Information Products and Product Information are Subject to Change Without Notice December 3, 2021 2