www.德州仪器.com
PhaseNoisePerformance
f − 频率 − hz
−160
−150
−140
−130
−120
−110
−100
−90
−80
−70
10 100 1k 100k 10M1M10k
l(f) − db
G009
CDCM7005在 pll−closed 循环
cdcm7005 evm
ref_在: agilente8257c−61.44mhz
vcxo: toyocom tco−2111 245.76mhz
cdcm7005 输出 是 y0a: 61.44mhz
循环 带宽 ~ 30hz
日期: 30. 三月 2005
阶段-噪音
分析器
E5052A
CDCM7005
ref_clk
LPF
VCXO
阶段 jitter (rms) − 1khz − 10mhz
LVPECL
61.44mhz (282fs)
Input−Clk
61.44mhz (769fs)
VXCO
245.76mhz (581fs)
LVCMOS
61.44mhz
(230fs)
CDCM7005
SCAS793A–JUNE2005–REVISEDJUNE2005
applicationinformation(持续)
ref_inphasevcxophaseyxphasenoise
noisenoiseat30.72mhz
参数
(1)
TESTCONDITIONSUNIT
at30.72mhzat245.76mhz
LVCMOSLVPECL
典型值
(2)
典型值
(2)
phn10phasenoiseat10hz–109–75–104–100dbc/hz
phn100phasenoiseat100hz–125–97–116–116dbc/hz
y=30.72mhz;f
PFD
=200
phn1kphasenoiseat1khz–134–117–140–140dbc/hz
khz,loopbw=20hz,
phn10kphasenoiseat10khzfeedbackdivider=8x128–136–138–153–152dbc/hz
(nxp),f
ref_在
=30.72mhz,
phn100kphasenoiseat100khz–138–148–156–153dbc/hz
m-分隔物=128,i
CP
=2mA
phn1mkphasenoiseat1mhz–144–148–156–153dbc/hz
phn10mphasenoiseat10mhz–144–148–156–153dbc/hz
PLLStabilizationTime
tstabiPLLstabilizationtime
(3)
y=30.72mhz,f
PFD
=200400ms
khz,loopbw=20hz,
FeedbackDivider=8x128
(nxp),f
ref_在
=30.72mhz,
m-分隔物=128,i
CP
=2mA
(1)outputphasenoiseisdependentonthenoiseoftheref_inclockandvcxoclocknoisefloor.thephasenoiseperformanceofthe
bgaandtheqfnpackageisequal.thephasenoisemeasurementsweretakenwiththecdcm7005evmandcdcm7005spidefault
settings.
(2)thetypicalstabilizationtimeisbasedontheaboveapplicationexample.thestabilizationcriterionwasastablehighlevelof
pll_锁.
(3)forfurtherexplanations,aswellasphasenoise/jittertestresultsusingvariousvcxos,seeapplicationnoteSCAA067.
figure25.phasenoise(61.44-mhzref_inand61.44-mhzoutputfrequency)
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