参数资料
型号: ICS843246AMLFT
元件分类: 时钟产生/分配
英文描述: 333.33 MHz, OTHER CLOCK GENERATOR, PDSO24
封装: 7.50 X 15.33 MM, 2.30 MM HEIGHT, ROHS COMPLIANT, MS-013, MO-119, SOIC-24
文件页数: 15/15页
文件大小: 205K
代理商: ICS843246AMLFT
843246AM
www.icst.com/products/hiperclocks.html
REV. A SEPTEMBER 29, 2005
9
Integrated
Circuit
Systems, Inc.
ICS843246
FEMTOCLOCKSCRYSTAL-TO-3.3V LVPECL
FREQUENCY SYNTHESIZER W/INTEGRATED FANOUT BUFFER
PRELIMINARY
TERMINATION FOR 3.3V LVPECL OUTPUT
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 termi-
nation for LVPECL outputs. The two different layouts men-
tioned are recommended only as guidelines.
FOUT and nFOUT are low impedance follower outputs that
generate ECL/LVPECL compatible outputs. Therefore, termi-
nating resistors (DC current path to ground) or current
sources must be used for functionality. These outputs are
FIGURE 3B. LVPECL OUTPUT TERMINATION
FIGURE 3A. LVPECL OUTPUT TERMINATION
designed to drive 50
Ω transmission lines. Matched imped-
ance techniques should be used to maximize operating
frequency and minimize signal distortion. Figures 3A and
3B show two different layouts which are recommended only
as guidelines. Other suitable clock layouts may exist and it
would be recommended that the board designers simulate to
guarantee compatibility across all printed circuit and clock
component process variations.
INPUTS:
LVCMOS CONTROL PINS:
All control pins have internal pull-ups or pull-downs; additional
resistance is not required but can be added for additional
protection. A 1k
Ω resistor can be used.
RECOMMENDATIONS FOR UNUSED INPUT AND OUTPUT PINS
OUTPUTS:
LVPECL OUTPUT
All unused LVPECL outputs can be left floating. We
recommend that there is no trace attached. Both sides of the
differential output pair should either be left floating or
terminated.
相关PDF资料
PDF描述
ICS843246AGT 333.33 MHz, OTHER CLOCK GENERATOR, PDSO24
ICS843246AMLF 333.33 MHz, OTHER CLOCK GENERATOR, PDSO24
ICS84324AMLFT 125 MHz, OTHER CLOCK GENERATOR, PDSO24
ICS84324DM 125 MHz, OTHER CLOCK GENERATOR, PDSO24
ICS843252AG-04 187.5 MHz, OTHER CLOCK GENERATOR, PDSO16
相关代理商/技术参数
参数描述
ICS843246AMT 制造商:ICS 制造商全称:ICS 功能描述:FEMTOCLOCKS⑩ CRYSTAL-TO-3.3V LVPECL FREQUENCY SYNTHESIZER W/INTEGRATED FANOUT BUFFER
ICS843246BGI 制造商:IDT 制造商全称:Integrated Device Technology 功能描述:FEMTOCLOCKS⑩ CRYSTAL-TO-3.3V LVPECL FREQUENCY SYNTHESIZER W/INTEGRATED FANOUT BUFFER
ICS843246BGILF 制造商:IDT 制造商全称:Integrated Device Technology 功能描述:FEMTOCLOCKS⑩ CRYSTAL-TO-3.3V LVPECL FREQUENCY SYNTHESIZER W/INTEGRATED FANOUT BUFFER
ICS843246BGILFT 制造商:IDT 制造商全称:Integrated Device Technology 功能描述:FEMTOCLOCKS⑩ CRYSTAL-TO-3.3V LVPECL FREQUENCY SYNTHESIZER W/INTEGRATED FANOUT BUFFER
ICS843246BGIT 制造商:IDT 制造商全称:Integrated Device Technology 功能描述:FEMTOCLOCKS⑩ CRYSTAL-TO-3.3V LVPECL FREQUENCY SYNTHESIZER W/INTEGRATED FANOUT BUFFER