Jitteris a random variation of the output clock. It is caused primarily by AVDD/AGND and substrate noise perturbing the VCO(Voltage Controled Oscillator) within the PLL. It can also be caused by excessive jitter on the REFCLK input. Output jitter is defined in three ways: period jitter. dut...
对于PLL,用的晶振存在不稳定性,而且会累加相位错误,而DLL在这点上做的好一些,抗噪声的能力强些;但PLL在时钟的综合方面做得更好些。总的来说PLL的应用多,DLL则在jitter power precision等方面优于PLL。 DLL数字电路与PLL模拟电路实现时有精确的时序,而数字电路实现时:抗噪声,低功耗,抗抖动,移植性...
(internal) VCXO = 122.88 MHz CLKinX = 30.72 MHz Example 2: LOS_LAT_SEL = 0000 1000 LOS_FRQ_DBL_EN = 1 VCXO = 122.88 MHz CLKinX = 122.88 MHz CNT reset CNT reset LOS (internal) LOS detection 0.5 RefCLK Cycles LOS_LAT_SEL CLKinX STATUSx Example 3: LOS_LAT_SEL = 0000 0010 LOS_...
(10 kHz to 20 MHz): – 48-fs RMS jitter at 1966.08 MHz – 50-fs RMS jitter at 983.04 MHz – 61-fs RMS jitter at 122.88 MHz • –165-dBc/Hz noise floor at 122.88 MHz • JESD204B support – Single shot, pulsed, and continuous SYSREF • 16 differential output clocks in 8 ...
Createan‘active_clk’signalTurnonorTurnTurnontocreatetheactiveclkoutput.Theactiveclkoutput toindicatetheinputclockinoffindicatestheinputclockwhichisinusebythePLL.Outputsignallow useindicatesrefclkandoutputsignalhighindicatesrefclk1. Createa‘clkbad’signalforTurnonorTurnTurnontocreatetwoclkbadoutputs,oneforeachin...
A | Page 4 of 44 Data Sheet AD9577 PLL1 CLOCK OUTPUT JITTER Table 2. Parameter1 Min Typ Max Unit Test Conditions/Comments2 LVPECL INTEGRATED RANDOM PHASE JITTER 25 MHz crystal used RMS Jitter (625 MHz Output) 460 750 fs rms 12 kHz to 20 MHz, Na = 100, Vx = 2, Dx = 2 430 ...
1. Instead of using IOPLL, try to use fPLL to drive the CDR refclk to see if it work. 2. Route the PLL output clock to Global Clock network and then connect back to the CDR refclk. You may use ALTCLKCTRL to force the PLL output clock to GCLK to see if ...
Output Clock Dividers (CLKOP, CLKOS, CLKOS2, CLKOS3) – The output clock dividers allow the VCO frequency to be scaled up to the 400–800 MHz range which minimizes jitter. Each of the output dividers is independent of the other dividers and each uses the VCO as the source by default...
another way i guess is to drive clock to these 2 REFCLK - s right from the crystal oscillator, with different trace lengths; then analyze phase difference of the arrival of clocks to the REFCLK-s. and use pll phase shift ability to align pll output clocks to each other and with...
(internal) VCXO = 122.88 MHz CLKinX = 30.72 MHz Example 2: LOS_LAT_SEL = 0000 1000 LOS_FRQ_DBL_EN = 1 VCXO = 122.88 MHz CLKinX = 122.88 MHz CNT reset CNT reset LOS (internal) LOS detection 0.5 RefCLK Cycles LOS_LAT_SEL CLKinX STATUSx Example 3: LOS_LAT_SEL = 0000 0010 LOS_...