参数资料
型号: I2781AF-08TT
厂商: ALLIANCE SEMICONDUCTOR CORP
元件分类: XO, clock
英文描述: General Purpose EMI Reduction IC
中文描述: 78 MHz, OTHER CLOCK GENERATOR, PDSO8
封装: ROHS COMPLIANT, TSSOP-8
文件页数: 1/11页
文件大小: 169K
代理商: I2781AF-08TT
July 2005
rev 1.5
P2781/82/84
Alliance Semiconductor
2575, Augustine Drive
Santa Clara, CA
Tel: 408.855.4900
Fax: 408.855.4999
www.alsc.com
Notice: The information in this document is subject to change without notice.
General Purpose EMI Reduction IC
Features
Provides up to 15dB of EMI suppression
FCC approved method of EMI attenuation
Generates a 1X, 2X, and 4X low EMI spread
spectrum clock of the input frequency
Input frequency range from 3 to 78MHz
External loop filter for spread % adjustment
Spreading ranges from ±0.25% to ±5.0%
Ultra low cycle-to-cycle jitter
Zero-cycle slip
3.3V operating voltage range
10 mA output drives
TTL or CMOS compatible outputs
Ultra-low power CMOS design
P278XA is available in 8 pin SOIC and TSSOP
Packages
Available for industrial and automotive
temperature ranges.
Product Description
The P278xA is a versatile spread spectrum frequency
modulator designed specifically for digital camera and
other digital video and imaging applications. The P278xA
reduces electromagnetic interference (EMI) at the clock
source, which provides system wide reduction of EMI of
all clock dependent signals. The P278xA allows
significant system cost savings by reducing the number of
circuit board layers and shielding that are traditionally
required to pass EMI regulations.
The P278xA uses the most efficient and optimized
modulation profile approved by the FCC. The P278xA
modulates the output of a single PLL in order to “spread”
the bandwidth of a synthesized clock and, more
importantly, decreases the peak amplitudes of its
harmonics. This results in significantly lower system EMI
compared to the typical narrow band signal produced by
oscillators and most frequency generators. Lowering EMI
by increasing a signal’s bandwidth is called spread
spectrum clock generation.
Applications
The P278xA is targeted towards MFP, xDSL, fax modem,
set-top box, USB controller, DSC, and embedded systems.
Block Diagram
Crystal
Oscillator
Frequency
Divider
Feedback
Divider
Phase
Detector
Modulation
Output
Divider
VCO
XIN /CLKIN
XOUT
FS0
FS1
LF
VDD
VSS
PLL
ModOUT
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相关代理商/技术参数
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I2781AG-08SR 功能描述:时钟发生器及支持产品 3-78MHZ 3.3V 1X GP EMI RoHS:否 制造商:Silicon Labs 类型:Clock Generators 最大输入频率:14.318 MHz 最大输出频率:166 MHz 输出端数量:16 占空比 - 最大:55 % 工作电源电压:3.3 V 工作电源电流:1 mA 最大工作温度:+ 85 C 安装风格:SMD/SMT 封装 / 箱体:QFN-56
I2781AG-08ST 制造商:ALSC 制造商全称:Alliance Semiconductor Corporation 功能描述:General Purpose EMI Reduction IC
I2781AG-08TR 制造商:PULSECORE 制造商全称:PulseCore Semiconductor 功能描述:General Purpose EMI Reduction IC
I2781AG-08TT 制造商:ALSC 制造商全称:Alliance Semiconductor Corporation 功能描述:General Purpose EMI Reduction IC
I2782A-08SR 制造商:ALSC 制造商全称:Alliance Semiconductor Corporation 功能描述:General Purpose EMI Reduction IC