ASM3I2969A-06OR
器件描述：Low Power Peak EMI Reducing Solution
器件厂商：ALSC [Alliance Semiconductor Corporation]
厂商主页：http://www.alsc.com/
文件大小：179.07KB，共12页
Sponsor by e络盟器件资料摘要：
September 2005 ASM3P2969A
rev 1.6
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.
Low Power Peak EMI Reducing Solution
Features
Generates an EMI optimized clock signal at the
output.
Integrated loop filter components.
Operates with a 3.3V / 2.5V supply.
Operating current less than 4mA.
Low power CMOS design.
Input frequency range: 6MHz to 12MHz for 2.5V
: 6MHz to 13MHz for 3.3V
Generates a 1X low EMI spread spectrum clock of
the input frequency.
Frequency deviation: ±1% @ 10MHz
Available in 6 pin TSOT-23, 8 pin SOIC and 8 pin
TSSOP Packages.
Product Description
The ASM3P2969A is a versatile spread spectrum
frequency modulator designed specifically for a wide
range of clock frequencies. The ASM3P2969A reduces
electromagnetic interference (EMI) at the clock source,
allowing system wide reduction of EMI of all clock
dependent signals. The ASM3P2969A allows significant
system cost savings by reducing the number of circuit
board layers ferrite beads, shielding that are traditionally
required to pass EMI regulations.
The ASM3P2969A uses the most efficient and optimized
modulation profile approved by the FCC and is
implemented by using a proprietary all digital method.
The ASM3P2969A 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 ASM3P2969A is targeted towards all portable
devices with very low power requirements like MP3
players, Notebooks and digital still cameras.
Key Specifications
Description Specification
Supply voltages VDD = 3.3V /2.5V
Cycle-to-Cycle Jitter 200pS (Max)
Output Duty Cycle 45/55%
Modulation Rate Equation F
IN
/256
Frequency Deviation ±1% @ 10MHz
Block Diagram
ModOUT
XOUT
REFOUT/2
XIN
VSS
Frequency
Divider
Feedback
Divider
Modulation
Phase
Detector
Loop
Filter
VCO
Output
Divider
PLL
VDD
Crystal
Oscillator
DIV/2
rev 1.6
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.
Low Power Peak EMI Reducing Solution
Features
Generates an EMI optimized clock signal at the
output.
Integrated loop filter components.
Operates with a 3.3V / 2.5V supply.
Operating current less than 4mA.
Low power CMOS design.
Input frequency range: 6MHz to 12MHz for 2.5V
: 6MHz to 13MHz for 3.3V
Generates a 1X low EMI spread spectrum clock of
the input frequency.
Frequency deviation: ±1% @ 10MHz
Available in 6 pin TSOT-23, 8 pin SOIC and 8 pin
TSSOP Packages.
Product Description
The ASM3P2969A is a versatile spread spectrum
frequency modulator designed specifically for a wide
range of clock frequencies. The ASM3P2969A reduces
electromagnetic interference (EMI) at the clock source,
allowing system wide reduction of EMI of all clock
dependent signals. The ASM3P2969A allows significant
system cost savings by reducing the number of circuit
board layers ferrite beads, shielding that are traditionally
required to pass EMI regulations.
The ASM3P2969A uses the most efficient and optimized
modulation profile approved by the FCC and is
implemented by using a proprietary all digital method.
The ASM3P2969A 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 ASM3P2969A is targeted towards all portable
devices with very low power requirements like MP3
players, Notebooks and digital still cameras.
Key Specifications
Description Specification
Supply voltages VDD = 3.3V /2.5V
Cycle-to-Cycle Jitter 200pS (Max)
Output Duty Cycle 45/55%
Modulation Rate Equation F
IN
/256
Frequency Deviation ±1% @ 10MHz
Block Diagram
ModOUT
XOUT
REFOUT/2
XIN
VSS
Frequency
Divider
Feedback
Divider
Modulation
Phase
Detector
Loop
Filter
VCO
Output
Divider
PLL
VDD
Crystal
Oscillator
DIV/2