Alliance Semiconductor
Product Proposal
AS80M2183/84
Jul., 2003 PulseCore – A Division of Alliance Semiconductor
Revision A 3160 De La Cruz Blvd., Suite 200 • Santa Clara • CA • 95054
Tel (408) 748-6988 • Fax (408) 748-0009
1 of 5
http://www.alsc.com
®
EMI Reduction IC
FEATURES
• FCC approved method of EMI attenuation
• Provides up to 15 dB EMI reduction
• Generates a 1X low EMI spread spectrum
clock from the input frequency
• Optimized for frequency range:
AS80M2183/84: 6 MHz to 70 MHz
• Internal loop filter minimizes external
components and board space
• AS80M2183: Down Spread
AS80M2184: Center Spread
• Low inherent cycle-to-cycle jitter
• 2 spread % selections:
AS80M2183: - 1.25% or – 3.75%
AS80M2184: +/- 0.625% or +/- 1.875%
• 3.3V operating voltage
• CMOS/TTL compatible inputs and outputs
• Low power CMOS design
• Supports notebook VGA and other LCD timing
controller applications
• Products are available for industrial
temperature range.
• Available in 8 pin SOIC and TSSOP
PRODUCT DESCRIPTION
The AS80M2183/84 is a versatile spread spectrum
frequency modulator designed specifically for a
wide range of input clock frequencies from 6 to 70
MHz (see Table 1). The AS80M2183/84 can
generate an EMI reduced clock from an OSC or a
system generated clock.
The AS80M2183/84 reduces electromagnetic
interference (EMI) at the clock source, allowing a
system wide EMI reduction for all the down stream
clocks and data dependent signals. The
AS80M2183/84 allows significant system cost
savings by reducing the number of circuit board
layers, ferrite beads, shielding, and other passive
components that are traditionally required to pass
EMI regulations.
The AS80M2183/84 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 system EMI compared to the
typical narrow band signal produced by oscillators
and most clock generators. Lowering EMI by
increasing a signal’s bandwidth is called “spread
spectrum clock generation”.
The AS80M2183/84 uses the most efficient and
optimized modulation profile approved by the FCC
and is implemented by using a proprietary all-
digital method.
APPLICATIONS
The AS80M2183/84 is targeted towards EMI
management for memory and LVDS interfaces in
mobile graphic chipsets and high-speed digital
applications such as PC peripheral devices,
consumer electronics, and embedded controller
systems.
Alliance Semiconductor
Product Proposal
AS80M2183/84
Jun., 2003 PulseCore – A Division of Alliance Semiconductor
Revision A 3160 De La Cruz Blvd., Suite 200 • Santa Clara • CA • 95054
Tel (408) 748-6988 • Fax (408) 748-0009
2 of 5
http://www.alsc.com
®
Figure 1 – AS80M2183/84 Pin Diagrams
FS0
XIN
VDD
MODOUT
AS80M2183/84
XOUT
GND
SS%
FS1
Figure 2 – AS80M2183/84 Block Diagram
Alliance Semiconductor
Product Proposal
AS80M2183/84
Jun., 2003 PulseCore – A Division of Alliance Semiconductor
Revision A 3160 De La Cruz Blvd., Suite 200 • Santa Clara • CA • 95054
Tel (408) 748-6988 • Fax (408) 748-0009
3 of 5
http://www.alsc.com
®
Table 1- Input Frequency and Modulation Rate
Part Number FS1 (pin 8) FS0 (pin 7) Frequency Range
0 0 6 MHz to 13 MHz
0 1 12 MHz to 25 MHz
1 0 18 MHz to 35 MHz
AS80M2183/84
1 1 40 MHz to 70 MHz
Table 2 - Spread Deviation Selections
Part Number SS% (pin 4) Spread Deviation
0 - 1.25%
AS80M2183
1 - 3.75%
0 +/- 0.625%
AS80M2184
1 +/- 1.875%
PIN DESCRIPTION
PIN # Name Type Description
1 XIN I Connect to externally generated clock signal.
2 XOUT I Crystal Connection.
3 GND P Ground.
4 SS% I Spread Range Select. Digital logic input used to select frequency deviation
(see Table 2). This pin has an internal pull-up resistor.
5 ModOut O Spread Spectrum low EMI output
6 VDD P Connect to +3.3V.
7 FS0 I Frequency range select. Digital Logic input used to select frequency range
(see Table 1). This pin has an internal pull-up resistor.
8 FS1 I Frequency range select. Digital Logic input used to select frequency range
(see Table 1). This pin has an internal pull-up resistor.
Alliance Semiconductor
Product Proposal
AS80M2183/84
Jun., 2003 PulseCore – A Division of Alliance Semiconductor
Revision A 3160 De La Cruz Blvd., Suite 200 • Santa Clara • CA • 95054
Tel (408) 748-6988 • Fax (408) 748-0009
4 of 5
http://www.alsc.com
®
ABSOLUTE MAXIMUM RATINGS
Symbol
Parameter Rating Unit
VDD, VIN Voltage on any pin with respect to GND -0.5 to +7.0 V
TSTG Storage Temperature -65 to +125 ºC
TA Operating Temperature 0 to +70 ºC
DC ELECTRICAL CHARACTERISTICS
Symbol Parameter
Min Typ Max Unit
VIL Input Low Voltage GND – 0.3 - 0.8 V
VIH Input High Voltage 2.0 - VDD+0.3 V
IIL Input Low Current - - -35 µA
IIH Input High Current - - 35
µA
IXOL
XOUT Output Low Current
(@ 0.4V, VDD = 3.3V)
- TBD - mA
IXOH
XOUT Output High Current
(@ 2.5V, VDD = 3.3V)
- TBD - mA
VOL Output Low Voltage
(VDD=3.3V, IOL = 20 mA)
- - 0.4 V
VOH Output High Voltage
(VDD=3.3V, IOH = 20 mA)
2.5 - - V
IDD Static Supply Current
Standby Mode
- 0.6 -
mA
ICC Dynamic Supply Current
Normal Mode (3.3V and 10 pF loading)
8.46 12 17.78 mA
VDD Operating Voltage 2.7 3.3 3.7 V
tON
Power Up Time
(First locked clock cycle after power up)
- 0.18 - mS
ZOUT Clock Output Impedance - 50 - Ω
AC ELECTRICAL CHARACTERISTICS
Symbol Parameter
Min Typ Max Unit
fIN Input Frequency 6 - 70 MHz
fOUT Output Frequency 6 - 70 MHz
tLH
Note 1
Output Rise Time
(measured at 0.8V to 2.0V)
0.7 0.9 1.1 ns
tHL
Note 1
Output Fall Time
(measured at 2.0V to 0.8V)
0.6 0.8 1.0 ns
tJC Jitter (cycle to cycle) - - 200 ps
tD Output Duty Cycle 45 50 55 %
Note1: tLH and tHL are measured into a capacitive load of 15pF
Alliance Semiconductor
Product Proposal
AS80M2183/84
Jun., 2003 PulseCore – A Division of Alliance Semiconductor
Revision A 3160 De La Cruz Blvd., Suite 200 • Santa Clara • CA • 95054
Tel (408) 748-6988 • Fax (408) 748-0009
5 of 5
http://www.alsc.com
®
Figure 3 - Mechanical Package Outline (8 Pin SOIC)
Figure 4 - Mechanical Package Outline (8 Pin TSSOP)
INCHES MILLIMETERS
SYMBOL MIN NOR MAX MIN NOR MAX
A 0.057 0.064 0.071 1.45 1.63 1.80
A1 0.004 0.007 0.010 0.10 0.18 0.25
A2 0.053 0.061 0.069 1.35 1.55 1.75
B 0.012 0.016 0.020 0.31 0.41 0.51
C 0.004 0.006 0.001 0.10 0.15 0.25
D 0.186 0.194 0.202 4.72 4.92 5.12
E 0.148 0.156 0.164 3.75 3.95 4.15
e 0.050 BSC 1.27 BSC
H 0.224 0.236 0.248 5.70 6.00 6.30
L 0.012 0.020 0.028 0.30 0.50 0.70
a 0° 5° 8° 0° 5° 8°
Note: Controlling dimensions are millimeters.
SOIC - 0.074
g
rams unit wei
g
ht
INCHES MILLIMETERS
SYMBOL MIN NOR MAX MIN NOR MAX
A - - 0.047 - - 1.10
A1 0.002 - 0.006 0.05 - 0.15
A2 0.031 0.039 0.041 0.80 1.00 1.05
B 0.007 - 0.012 0.19 - 0.30
C 0.004 - 0.008 0.09 - 0.20
D 0.114 0.118 0.122 2.90 3.00 3.10
E 0.169 0.173 0.177 4.30 4.40 4.50
e 0.026 BSC 0.65 BSC
H 0.244 0.252 0.260 6.20 6.40 6.60
L 0.018 0.024 0.030 0.45 0.60 0.75
a 0° - 8° 0° - 8°
Note: Controlling dimensions are millimeters.
TSSOP - 0.034 grams unit weight
