ASM3P2180A
Peak Reducing
EMI Solution
Product Description
The ASM3P2180A is a versatile spread spectrum frequency
modulator designed specifically for a wide range of clock frequencies. www.onsemi.com
ASM3P2180A reduces electromagnetic interference (EMI) at the
clock source, allowing system wide reduction of EMI of down stream
8
clock and data dependent signals. ASM3P2180A allows significant
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system cost savings by reducing the number of circuit board layers,
and shielding that are traditionally required to pass EMI regulations.
SOIC8 NB
CASE 751
ASM3P2180A modulates the output of a single PLL in order to
spread the bandwidth of a synthesized clock, thereby decreasing the
peak amplitudes of its harmonics. This results in significantly lower
PIN CONNECTION
system EMI compared to the typical narrow band signal produced by
oscillators and most clock generators. Lowering EMI by increasing
CLKIN/XIN 1 NC
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asignals bandwidth is called spread spectrum clock generation.
ASM3P2180A uses the most efficient and optimized modulation
2 7
XOUT FS
profile approved by the FCC and is implemented by using
ASM3P2180A
a proprietary all-digital method.
GND 3 6 VDD
Features
45
SS% CLKOUT
Generates a 1x EMI Optimized Clock Output
Input Frequency:
6 MHz 10 MHz
MARKING DIAGRAM
18 MHz 30 MHz
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Output Frequency:
6 MHz 10 MHz ACT
ALYWX
18 MHz 30 MHz
Two Selectable Down Spread Options
Selectable Frequency Range
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Integrated Loop Filter Components
ACT = Specific Device Code
A = Assembly Location
Operates with a 3.3 V Supply
L = Wafer Lot
CMOS Design
Y = Year
8-Pin SOIC Packages
W = Work Week
= Pb-Free Package
This Device is Pb-Free, Halogen Free and is RoHS Compliant
(Note: Microdot may be in either location)
Applications
The ASM3P2180A is targeted towards notebook LCD displays,
ORDERING INFORMATION
other displays using an LVDS interface, PC peripheral devices and
See detailed ordering and shipping information on page 4 of
this data sheet.
embedded systems.
Semiconductor Components Industries, LLC, 2016
1 Publication Order Number:
July, 2016 Rev. 4 ASM3P2180/DASM3P2180A
SS%
VDD FS
Modulation
CLKIN/XIN
CLKOUT
Crystal
XOUT Oscillator
PLL
GND
Figure 1. Block Diagram
CLKIN/XIN 1 8 NC
2 7
XOUT FS
3P2180A
GND 3 6 VDD
SS%45 CLKOUT
Figure 2. Pin Diagram
Table 1. PIN DESCRIPTION
Pin# Pin Name Type Description
1 CLKIN/XIN I Crystal Connection or External Reference Clock Input
2 XOUT O Connection for an External Crystal. If using an External Reference, this Pin must be Left
Unconnected
3 GND P Ground to Entire Chip
4 SS% I Spread Selection Input. Has an Internal Pull-Up Resistor
5 CLKOUT O Modulated Clock Output
6 VDD P Power Supply for the Entire Chip
7 FS I Frequency Selection Bit. This Pin Selects the Frequency Range of Operation (See Table 2).
Has an Internal Pull-Up Resistor
8 NC No Connect
Table 2. FREQUENCY RANGE SELECTION
FS Frequency Range (MHz)
0 610
1 1830
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