Silicon Lab Si5348网络同步时钟开发方案

Silicon Lab公司的Si5348是网络同步时钟器,用于SyncE/ 1588 PTP电信边界(T-BC)和从(T-SC)时钟,提供三个DSPLL.能通过串行接口单独配置和控制.每个DSPLL支持锁住,自由运行,以及具有选择DCO模式的运营滞留模式,以用于IEEE 1588应用.器件需要外接晶振和外接基准(TCXO或OCXO)来运行.基准输入(REF/REFb)确定了自由运行和滞留模式的频率精确度和稳定性.时钟的超低抖动为95fs,增强无障碍切换最小化输出相位瞬变,输入频率范围:外接晶体48-54MHz,REF时钟5-250MHz,差分时钟8kHz到750MHz,LVCMOS时钟:8 kHz 到250 MHz;输出频率范围:差分1 PPS 到 718.5 MHz, LVCMOS 1 PPS到 250 MHz.器件满足以下规范:ITU-T G.8262 (SyncE) EEC Options 1and 2, ITU-T G.812 Type III, IV, ITU-T G.813 Option 1和Telcordia GR-1244, GR-253(Stratum-3/3E).主要用在同步以太网(SyncE)ITU-T G.8262 EEC Option 1 & 2,由ITU-T G.8273.2所定义的电信边界时钟(T-BC),IEEE 1588 (PTP)从时钟同步化,以及Stratum 3/3E, G.812, G.813网络同步.本文介绍了Si5348主要特性,框图和Si5348-E详细框图,以及开发板Si5348-E-EVB主要特性,功能框图,应用框图和电路图,材料清单和PCB设计图.
The Si5348 offers three DSPLLs that can be independently configured and controlled through the serial interface. Each of the DSPLLssupport locked, free-run, and holdover modes of operation with an optional DCO mode for IEEE 1588 applications. The device requiresan external crystal and an external reference (TCXO or OCXO) to operate. The reference input (REF/REFb) determines the frequencyaccuracy and stability while in free-run and holdover modes. The external crystal completes the internal oscillator circuit (OSC) which isused by the DSPLL for intrinsic jitter performance. There are three main inputs (IN0 - IN2) for synchronizing the DSPLLs. Input selectioncan be manual or automatically controlled using an internal state machine. Two additional manually selected inputs are available toDSPLL D. Any of the output clocks (OUT0 to OUT6) can be configured to any of the DSPLLs using a flexible crosspoint connection.
Output 6 is the only output that can be configured for a 1 Hz output to support 1 PPS. The Si...