参数资料
型号: ICS840245AGIT
厂商: INTEGRATED DEVICE TECHNOLOGY INC
元件分类: 时钟产生/分配
英文描述: 75 MHz, OTHER CLOCK GENERATOR, PDSO16
封装: 4.40 X 5 MM, 0.92 MM HEIGHT, MO-153, TSSOP-16
文件页数: 13/13页
文件大小: 1406K
代理商: ICS840245AGIT
IDT / ICS LVCMOS/LVTTL FREQUENCY SYNTHESIZER
9
ICS84024AGI REV. A OCTOBER 25, 2006
ICS840245I
FEMTOCLOCKS 1:5, CRYSTAL-TO-LVCMOS/LVTTL FREQUENCY SYNTHESIZER
CRYSTAL INPUT INTERFACE
The ICS840245I has been characterized with 18pF parallel
resonant crystals. The capacitor values shown in
Figure 2 below
Figure 2. CRYSTAL INPUt INTERFACE
were determined using a 25MHz 18pF parallel resonant crystal
and were chosen to minimize the ppm error.
ICS84332
XTAL_IN
XTAL_OUT
X1
18pF Parallel Cry stal
C2
22p
C1
22p
ICS840245I
TBD
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
applications, R1
and R2 can be 100
. This can also be accomplished by removing
R1 and making R2 50
.
R2
Zo = 50
VDD
Ro
Zo = Ro + Rs
R1
VDD
XTAL_IN
XTAL_OUT
.1uf
Rs
相关PDF资料
PDF描述
ICS840245AGI 75 MHz, OTHER CLOCK GENERATOR, PDSO16
ICS843201AG-375 375 MHz, OTHER CLOCK GENERATOR, PDSO16
ICS843201AG-375T 375 MHz, OTHER CLOCK GENERATOR, PDSO16
ICS843201AG-375LF 375 MHz, OTHER CLOCK GENERATOR, PDSO16
ICS8440258AK-46LFT 125 MHz, OTHER CLOCK GENERATOR, QCC32
相关代理商/技术参数
参数描述
ICS84025 制造商:ICS 制造商全称:ICS 功能描述:CRYSTAL-TO-LVCMOS / LVTTL FREQUENCY SYNTHESIZER WITH FANOUT BUFFER
ICS84025EM 制造商:ICS 制造商全称:ICS 功能描述:CRYSTAL-TO-LVCMOS / LVTTL FREQUENCY SYNTHESIZER WITH FANOUT BUFFER
ICS84025EMT 制造商:ICS 制造商全称:ICS 功能描述:CRYSTAL-TO-LVCMOS / LVTTL FREQUENCY SYNTHESIZER WITH FANOUT BUFFER
ICS840271BGILF 功能描述:IC TRANSLATOR ETHER SYNC 8TSSOP RoHS:是 类别:集成电路 (IC) >> 时钟/计时 - 专用 系列:HiPerClockS™ 标准包装:1,500 系列:- 类型:时钟缓冲器/驱动器 PLL:是 主要目的:- 输入:- 输出:- 电路数:- 比率 - 输入:输出:- 差分 - 输入:输出:- 频率 - 最大:- 电源电压:3.3V 工作温度:0°C ~ 70°C 安装类型:表面贴装 封装/外壳:28-SSOP(0.209",5.30mm 宽) 供应商设备封装:28-SSOP 包装:带卷 (TR) 其它名称:93786AFT
ICS840271BGILFT 功能描述:IC TRANSLATOR ETHER SYNC 8TSSOP RoHS:是 类别:集成电路 (IC) >> 时钟/计时 - 专用 系列:HiPerClockS™ 标准包装:1,500 系列:- 类型:时钟缓冲器/驱动器 PLL:是 主要目的:- 输入:- 输出:- 电路数:- 比率 - 输入:输出:- 差分 - 输入:输出:- 频率 - 最大:- 电源电压:3.3V 工作温度:0°C ~ 70°C 安装类型:表面贴装 封装/外壳:28-SSOP(0.209",5.30mm 宽) 供应商设备封装:28-SSOP 包装:带卷 (TR) 其它名称:93786AFT