ALSC ASM3P2811A Low power emi reduction ic Datasheet

September 2003
ASM3P2811A/B
ASM3P2812A/B
ASM3P2814A/B
rev 1.0
Low Power EMI Reduction IC
Features
FCC approved method of EMI attenuation.
Provides up to 15dB EMI reduction.
Generates a 1X, 2X and 4X low EMI spread
spectrum clock of the input frequency.
o
1X: ASM3P2811A/B
o
2X: ASM3P2812A/B
o
4X: ASM3P2814A/B
ASM3P2811A/B: 10 to 40MHz
o
ASM3P2812A/B: 10 to 40MHz
o
ASM3P2814A/B: 10 to 40MHz
Internal loop filter minimizes external components
and board space.
Selectable spread options: Down Spread and
Center Spread.
ferrite beads, shielding, and other passive components
that are traditionally required to pass EMI regulations.
The ASM3P28XX 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
8 spread frequency deviation selections:
spectrum clock generation’.
±0.625% to –3.5%
Low inherent cycle-to-cycle jitter.
The ASM3P28XX uses the most efficient and optimized
3.3V operating voltage range.
CMOS/TTL compatible inputs and outputs.
with
down stream clock and data dependent
savings by reducing the number of circuit board layers,
o
compatible
(EMI) at the clock source, allowing system wide reduction
signals. The ASM3P28XX allows significant system cost
to 40 MHz.
Pinout
The ASM3P28XX reduces electromagnetic interference
of EMI of
Optimized for input frequency range from 10MHz
o
deviation range from ±0.625% to –3.50%.
Cypress
CY25811,
modulation profile approved by the FCC and is
implemented in a proprietary all-digital method.
CY25812 and CY25814.
Products are available for industrial temperature
range.
Applications
The ASM3P28XX is targeted towards EMI management
Available in 8-pin SOIC and TSSOP.
for memory and LVDS interfaces in mobile graphic
chipsets and high-speed digital applications such as PC
Product Description
peripheral devices, consumer electronics, and embedded
The ASM3P28XX devices are versatile spread spectrum
controller systems.
frequency modulators designed specifically for a wide
range of input clock frequencies from 10MHz to 40MHz.
(Refer Input/Output Frequency Range Selection Table).
The ASM3P28XX can generate an EMI reduced clock
from
crystal, ceramic resonator, or system clock. The
ASM3P28XX-A and the ASM3P28XX-B offer various
combinations
of
spread
options
and
percentage
deviations (Refer Output Frequency Deviation and
Spread Option Selection Table). These combinations
include Down and Center Spread and percentage
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.
September 2003
ASM3P2811A/B
ASM3P2812A/B
ASM3P2814A/B
rev 1.0
Block Diagram
VDD
D_C SRS FRS
PLL
Modulation
XIN
Crystal
Oscillator
XOUT
Frequency
Divider
Phase
Detector
Feedback
Divider
Loop
Filter
VCO
Output
Divider
ModOUT
VSS
Pin Configuration
XIN
1
VSS
2
D_C
3
ASM3P2811A/B
ASM3P2812A/B
8
XOUT
7
VDD
6
FRS
5
ModOUT
ASM3P2814A/B
SRS
4
Low Power EMI Reduction IC
Notice: The information in this document is subject to change without notice.
2 of 6
September 2003
ASM3P2811A/B
ASM3P2812A/B
ASM3P2814A/B
rev 1.0
Pin Description
Pin#
Pin Name
Type
Description
1
XIN
I
Crystal connection or external frequency input. This pin has dual functions.
It can be connected to either an external crystal or an external reference
clock.
2
VSS
P
Ground to entire chip.
3
D_C
I
4
SRS
I
5
ModOUT
O
6
FRS
I
7
VDD
P
Power supply for the entire chip (3.3V).
8
XOUT
I
Crystal connection. Input connection for an external crystal. If using an
external reference, this pin must be left unconnected.
Digital logic input used to select Down (LOW) or Center (HIGH) spread
options. (Refer Output Frequency Deviation and Spread Option Selection
Table). This pin has an internal pull-up resistor.
Spread range select. Digital logic input used to select frequency deviation
(Refer Output Frequency Deviation and Spread Option Selection Table).
This pin has an internal pull-up resistor.
Spread spectrum clock output (Refer Input/Output Frequency Range
Selection Table and Output Frequency Deviation and Spread Option
Selection Table).
Frequency range select. Digital logic input used to select input frequency
range (Refer Input/Output Frequency Deviation and Spread Option
Selection Table). This pin has an internal pull-up resistor.
Input/Output Frequency Range Selection Table
Part Number
FRS (pin 6)
ASM3P2811 (1X)
ASM3P2812 (2X)
ASM3P2814 (4X)
Modulation Rate
Input
(MHz)
Output
(MHz)
Input
(MHz)
Output
(MHz)
Input
(MHz)
Output
(MHz)
0
10-20
10-20
10-20
20-40
10-20
40-80
Input Frequency / 448
1
20-40
20-40
20-40
40-80
20-40
80-160
Input Frequency / 896
Low Power EMI Reduction IC
Notice: The information in this document is subject to change without notice.
3 of 6
September 2003
ASM3P2811A/B
ASM3P2812A/B
ASM3P2814A/B
rev 1.0
Output Frequency Deviation and Spread Option Selection Table
Part Number
D_C (pin 3)
SRS (pin 4)
Output frequency deviation
and spread option
0
0
-2.50% (Down)
0
1
-3.50% (Down)
1
0
± 1.25% (Center)
1
1
±1.75% (Center)
0
0
-1.25% (Down)
0
1
-1.75% (Down)
1
0
± 0.625% (Center)
1
1
± 0.875% (Center)
ASM3P28XXA
ASM3P28XXB
Absolute Maximum Ratings
Symbol
Parameter
VDD, VIN
Voltage on any pin with respect to GND
TSTG
Storage temperature
TA
Operating temperature
Rating
Unit
-0.5 to + 7.0
V
-65 to +125
°C
0 to 70
°C
Note: These are stress ratings only and functional operation is not implied. Exposure to absolute maximum
ratings for extended periods may affect device reliability.
Low Power EMI Reduction IC
Notice: The information in this document is subject to change without notice.
4 of 6
September 2003
ASM3P2811A/B
ASM3P2812A/B
ASM3P2814A/B
rev 1.0
DC Electrical Characteristics (3.3V, 25°C)
Symbol
Parameter
Min
Typ
Max
Unit
VIL
Input low voltage
GND – 0.3
-
0.8
V
VIH
Input high voltage
-
-
VDD + 0.3
V
IIL
Input low current
(inputs D_C, SRS and FRS)
-60.00
-
-20.00
µA
-
-
1.00
µA
2.00
-
12.00
mA
-
-
12.00
mA
IIH
IXOL
IXOH
Input high current
XOUT Output low current
(@ 0.4V, VDD = 3.3V)
XOUT Output high current
(@ 2.5V, VDD = 3.3V)
VOL
Output low voltage (VDD = 3.3V, IOL = 20mA)
-
-
0.4
V
VOH
Output high voltage (VDD = 3.3V, IOH = 20mA)
2.8
-
-
V
7.1 fIN - min
-
13.9 fIN - max
mA
-
4.5
-
mA
IDD
Dynamic supply current
Normal mode (3.3V and 25pF loading)
Static supply current
Standby mode
VDD
Operating voltage
-
3.3
-
V
tON
Power up time (first locked clock cycle after power
up)
-
0.18
-
mS
ZOUT
Clock out impedance
-
50
-
Ω
ICC
AC Electrical Characteristics
Symbol
fIN
fOUT
Parameter
Min
Typ
Max
Unit
Input frequency ASM3P2811/12/13/14 A/B
10
-
40
MHz
Output frequency for ASM3P211A/B
10
-
40
MHz
Output frequency for AS3P2812A/B
20
-
80
MHz
Output frequency for AS3P2814A/B
40
-
160
MHz
tLH*
Output rise time (measured at 0.8V to 2.0V)
-
0.69
-
ns
tHL*
Output fall time (measured at 2.0V to 0.8V)
-
0.66
-
ns
tJC
Jitter (cycle to cycle)
-200
-
200
ps
TD
Output duty cycle
45
50
55
%
* tLH and tHL are measured into a capacitive load of 15pF
Low Power EMI Reduction IC
Notice: The information in this document is subject to change without notice.
5 of 6
September 2003
ASM3P2811A/B
ASM3P2812A/B
ASM3P2814A/B
rev 1.0
Package Information
8-Pin SOIC
H
E
D
A2
A
C
θ
e
A1
B
Symbol Dimensions in inches
D
L
Dimensions in millimeters
Min
Max
Min
Max
A
0.057
0.071
1.45
1.80
A1
0.004
0.010
0.10
0.25
A2
0.053
0.069
1.35
1.75
B
0.012
0.020
0.31
0.51
C
0.004
0.01
0.10
0.25
D
0.186
0.202
4.72
5.12
E
0.148
0.164
3.75
4.15
E
0.050 BSC
1.27 BSC
H
0.224
0.248
5.70
6.30
L
0.012
0.028
0.30
0.70
θ
0°
8°
0°
8°
Note: Controlling dimensions are millimeters.
SOIC: 0.074 grams unit weight.
Low Power EMI Reduction IC
Notice: The information in this document is subject to change without notice.
6 of 6
September 2003
ASM3P2811A/B
ASM3P2812A/B
ASM3P2814A/B
rev 1.0
8-Pin TSSOP
H
E
D
A2
A
C
θ
e
A1
L
B
Dimensions in inches
Symbol
Min
A
0.047
A1
0.002
0.006
0.05
0.15
A2
0.031
0.041
0.80
1.05
B
0.007
0.012
0.19
0.30
C
0.004
0.008
0.09
0.20
D
0.114
0.122
2.90
3.10
E
0.169
0.177
4.30
4.50
E
Max
Dimensions in millimeters
Min
Max
1.10
0.026 BSC
0.65 BSC
H
0.244
0.260
6.20
6.60
L
0.018
0.030
0.45
0.75
θ
0°
8°
0°
8°
Note: Controlling dimensions are millimeters.
TSSOP: 0.034 grams unit weight.
Low Power EMI Reduction IC
Notice: The information in this document is subject to change without notice.
7 of 7
September 2003
ASM3P2811A/B
ASM3P2812A/B
ASM3P2814A/B
rev 1.0
Alliance Semiconductor Corporation
2595, Augustine Drive,
Santa Clara, CA 95054
Tel# 408-855-4900
Fax: 408-855-4999
www.alsc.com
Copyright © Alliance Semiconductor
All Rights Reserved
Preliminary Information
Part Numbers: ASM3P2811A/B
ASM3P2812A/B
ASM3P2814A/B
Document Version: v1.0
© Copyright 2003 Alliance Semiconductor Corporation. All rights reserved. Our three-point logo, our name and Intelliwatt are
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Low Power EMI Reduction IC
Notice: The information in this document is subject to change without notice.
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