IDT / ICS 3.3V LVPECL FREQUENCY SYNTHESIZ" />
參數(shù)資料
型號: ICS843256BGLFT
廠商: IDT, Integrated Device Technology Inc
文件頁數(shù): 16/16頁
文件大小: 0K
描述: IC SYNTHESIZER W/BUFF 24-TSSOP
標(biāo)準(zhǔn)包裝: 2,500
系列: HiPerClockS™, FemtoClock™
類型: 頻率合成器
PLL: 帶旁路
輸入: 晶體
輸出: LVPECL
電路數(shù): 1
比率 - 輸入:輸出: 1:6
差分 - 輸入:輸出: 無/是
頻率 - 最大: 625MHz
除法器/乘法器: 是/無
電源電壓: 3.135 V ~ 3.465 V
工作溫度: 0°C ~ 70°C
安裝類型: 表面貼裝
封裝/外殼: 24-TSSOP(0.173",4.40mm 寬)
供應(yīng)商設(shè)備封裝: 24-TSSOP
包裝: 帶卷 (TR)
其它名稱: 843256BGLFT
IDT / ICS 3.3V LVPECL FREQUENCY SYNTHESIZER
9
ICS843256BG REV. A MAY 23, 2007
ICS843256
FEMTOCLOCKS CRYSTAL-TO-3.3V LVPECL FREQUENCY SYNTHESIZER
LVCMOS TO XTAL INTERFACE
The XTAL_IN input can accept a single-ended LVCMOS signal
through an AC coupling capacitor. A general interface diagram is
shown in Figure 3 The XTAL_OUT pin can be left floating. The
input edge rate can be as slow as 10ns. For LVCMOS inputs, it is
recommended that the amplitude be reduced from full swing to
half swing in order to prevent signal interference with the power
rail and to reduce noise. This configuration requires that the output
FIGURE 3. GENERAL DIAGRAM FOR LVCMOS DRIVER TO XTAL INPUT INTERFACE
impedance of the driver (Ro) plus the series resistance (Rs) equals
the transmission line impedance. In addition, matched termination
at the crystal input will attenuate the signal in half. This can be
done in one of two ways. First, R1 and R2 in parallel should equal
the transmission line impedance. For most 50
Ω applications, R1
and R2 can be 100
Ω. This can also be accomplished by removing
R1 and making R2 50
Ω.
R2
Zo = 50
VDD
Ro
Zo = Ro + Rs
R1
VDD
XTAL_IN
XTAL_OUT
.1uf
Rs
V
CC - 2V
50
Ω
50
Ω
RTT
Z
o = 50Ω
Z
o = 50Ω
FOUT
FIN
RTT =
Z
o
1
((V
OH + VOL) / (VCC – 2)) – 2
3.3V
125
Ω
125
Ω
84
Ω
84
Ω
Z
o = 50Ω
Z
o = 50Ω
FOUT
FIN
The clock layout topology shown below is a typical termination
for LVPECL outputs. The two different layouts mentioned are
recommended only as guidelines.
FOUT and nFOUT are low impedance follower outputs that gen-
erate ECL/LVPECL compatible outputs. Therefore, terminating
resistors (DC current path to ground) or current sources must be
used for functionality. These outputs are designed to drive 50
Ω
transmission lines. Matched impedance techniques should be
used to maximize operating frequency and minimize signal dis-
tortion. Figures 4A and 4B show two different layouts which are
recommended only as guidelines. Other suitable clock layouts
may exist and it would be recommended that the board design-
ers simulate to guarantee compatibility across all printed circuit
and clock component process variations.
TERMINATION FOR LVPECL OUTPUTS
FIGURE 4B. LVPECL OUTPUT TERMINATION
FIGURE 4A. LVPECL OUTPUT TERMINATION
相關(guān)PDF資料
PDF描述
AD5543BRMZ IC DAC 16BIT SERIAL-IN 8-MSOP
VE-B63-MV-F2 CONVERTER MOD DC/DC 24V 150W
VE-JTT-MZ-F1 CONVERTER MOD DC/DC 6.5V 25W
AD5543BRZ IC DAC 16BIT SRLIN/CUR OUT 8SOIC
VE-B63-MV-F1 CONVERTER MOD DC/DC 24V 150W
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
ICS843256CK-24LF 功能描述:IC SYNNTHESIZE 6LVPECL 32-VFQFPN RoHS:是 類別:集成電路 (IC) >> 時鐘/計時 - 時鐘發(fā)生器,PLL,頻率合成器 系列:HiPerClockS™, FemtoClock™ 標(biāo)準(zhǔn)包裝:27 系列:Precision Edge® 類型:頻率合成器 PLL:是 輸入:PECL,晶體 輸出:PECL 電路數(shù):1 比率 - 輸入:輸出:1:1 差分 - 輸入:輸出:無/是 頻率 - 最大:800MHz 除法器/乘法器:是/無 電源電壓:3.135 V ~ 5.25 V 工作溫度:0°C ~ 85°C 安裝類型:表面貼裝 封裝/外殼:28-SOIC(0.295",7.50mm 寬) 供應(yīng)商設(shè)備封裝:28-SOIC 包裝:管件
ICS843256CK-24LFT 功能描述:IC SYNNTHESIZE 6LVPECL 32-VFQFPN RoHS:是 類別:集成電路 (IC) >> 時鐘/計時 - 時鐘發(fā)生器,PLL,頻率合成器 系列:HiPerClockS™, FemtoClock™ 標(biāo)準(zhǔn)包裝:27 系列:Precision Edge® 類型:頻率合成器 PLL:是 輸入:PECL,晶體 輸出:PECL 電路數(shù):1 比率 - 輸入:輸出:1:1 差分 - 輸入:輸出:無/是 頻率 - 最大:800MHz 除法器/乘法器:是/無 電源電壓:3.135 V ~ 5.25 V 工作溫度:0°C ~ 85°C 安裝類型:表面貼裝 封裝/外殼:28-SOIC(0.295",7.50mm 寬) 供應(yīng)商設(shè)備封裝:28-SOIC 包裝:管件
ICS84325EM 制造商:ICS 制造商全稱:ICS 功能描述:CRYSTAL-TO-3.3V LVPECL FREQUENCY SYNTHESIZER WITH FANOUT BUFFER
ICS84325EMLN 制造商:ICS 制造商全稱:ICS 功能描述:CRYSTAL-TO-3.3V LVPECL FREQUENCY SYNTHESIZER WITH FANOUT BUFFER
ICS84325EMLNT 制造商:ICS 制造商全稱:ICS 功能描述:CRYSTAL-TO-3.3V LVPECL FREQUENCY SYNTHESIZER WITH FANOUT BUFFER