A2811A-08ST [ALSC]
Low-Power EMI Reduction IC; 低功耗的降低EMI IC
| 型号： | A2811A-08ST |
| 厂家： | 
ALLIANCE SEMICONDUCTOR CORPORATION |
| 描述： | Low-Power EMI Reduction IC |
| 文件： | 总8页 (文件大小：376K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
October 2003
rev
P2811/12/14
Low-Power EMI Reduction IC
Features
Deviation and Spread Option Selections section). These
combinations include Down Spread, Center Spread and
percentage deviation range from ±0.625% to -3.50%.
FCC approved method of EMI attenuation
Provides up to 15 dB EMI reduction
Generates 1X, 2X, and 4X low EMI spread spectrum
clock of the input frequency
The P28xx 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 P28xx 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.
1X: P2811, 2X: P2812, 4X: P2814
Optimized for input frequency range from 10 to 40
MHz P2811: 10 to 40 MHz P2812: 10 to 40 MHz
P2814: 10 to 40 MHz
Internal loop filter minimizes external components
and board space
Selectable spread options: Down Spread and Center
Spread
Low inherent cycle-to-cycle jitter
Eight spread % selections: ±0.625% to –3.5%
3.3 V operating voltage
CMOS/TTL compatible inputs and outputs
Pinout compatible with Cypress CY25811,
CY25812, and CY25814
Products available for industrial temperature range
Available in 8-pin SOIC and TSSOP
The P28xx 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 P28xx uses the most efficient and optimized
modulation profile approved by the FCC and is
implemented by using a proprietary all-digital method.
Applications
Product Description
The P28xx is targeted towards EMI management for
memory interfaces in mobile graphic chipsets and high-
speed digital applications such as PC peripheral devices,
consumer electronics, and embedded controller systems.
The P28xx is a versatile spread spectrum frequency
modulator designed specifically for input clock frequencies
from 10 to 40 MHz (see Input/Output Frequency Range
Selections). The P28xx can generate an EMI reduced clock
from crystal, ceramic resonator, or system clock. The
P28xx-A and P28xx-B offer various combinations of spread
options and percentage deviations (see Output Frequency
Block Diagram
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.
October 2003
P2811/12/14
rev
Pin Configuration
Pin Description
Pin#
1
2
Pin Name
Type
Description
XIN
I
Connect to externally generated clock signal or crystal.
VSS
D_C
P
I
Ground Connection. Connect to system ground.
Digital logic input used to select Down (LOW) or Center (HIGH) Spread
Options (see Output Frequency Deviation and Spread Option Selections).
This pin has an internal pull-up resistor.
Spread Range Selection. Digital logic input used to select frequency
deviation (see Output Frequency Deviation and Spread Option Selections).
This pin has an internal pull-up resistor.
Spread Spectrum clock output (see Input/Output Frequency Range
Selections and Output Frequency Deviation and Spread Option Selections).
Frequency Range Selection. Digital logic input used to select input fre-
quency range (see Input/Output Frequency Range Selections). This pin has
an internal pull-up resistor.
3
SRS
I
4
5
6
ModOut
FRS
O
I
VDD
P
I
Connect to +3.3 V
7
8
XOUT
Connect to crystal. No connect if externally generated clock signal is used.
Input/Output Frequency Range Selections
Part number
P2812 (2X)
Pin 6
Modulation
rate
P2811 (1X)
P2814 (4X)
Input
Output
(MHz)
Input
Output
Input
Output
(MHz)
FRS
(MHz)
(MHz)
(MHz)
(MHz)
Input frequency
/ 448
Input frequency
/ 896
0
1
10-20
10-20
10-20
20-40
10-20
40-80
20-40
20-40
20-40
40-80
20-40
80-160
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Notice: The information in this document is subject to change without notice.
October 2003
P2811/12/14
rev
Output Frequency Deviation and Spread Option Selections
Output frequency deviation and
Part number
Pin 3 D_C
Pin 4 SRS
spread option
-2.50% (Down)
-3.50% (Down)
+/-1.25% (Center)
+/-1.75% (Center)
0
0
1
1
0
1
0
1
P2811/12/14A
0
0
1
1
0
1
0
1
-1.25% (Down)
-1.75% (Down)
+/-0.625% (Center)
+/-0.875% (Center)
P2811/12/14B
Absolute Maximum Ratings
Symbol
Parameter
Rating
Unit
V
°C
°C
VDD, VIN
TSTG
Voltage on any pin with respect to GND
Storage temperature
-0.5 to + 7.0
-65 to +125
0 to 70
TA
Operating temperature
DC Electrical Characteristics
3.3 V, 25° C
Symbol
VIL
Parameter
Input Low Voltage
Input High Voltage
Min
GND – 0.3
–
Typ
–
–
Max
0.8
VDD + 0.3
Unit
V
V
VIH
Input low Current (inputs
D_C, SRS, and FRS)
IIL
IIH
-60.00
–
–
–
–
-20.00
1.00
µA
µA
Input High Current
XOUT Output Low Current
(@ 0.4V, VDD = 3.3V)
XOUT Output High Current
(@ 2.5V, VDD = 3.3V)
Output Low Voltage
IXOL
2.00
12.00
mA
IXOH
VOL
VOH
IDD
–
–
–
–
–
–
12.00
0.4
2.8
–
mA
V
(VDD=3.3V, IOL = 20 mA)
Output High Voltage
–
V
(VDD=3.3V, IOH = 20 mA)
Static Supply Current
Standby Mode
4.5
mA
Dynamic Supply Current
Normal Mode (3.3V and 25
pF probe loading)
ICC
7.1 fIN-min
–
13.9 fIN-max
mA
VDD
tON
Operating Voltage
–
–
–
3.3
0.18
50
–
–
–
V
mS
Ω
Power Up Time (First locked
clock cycle after power up)
ZOUT
Clock Output Impedance
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Notice: The information in this document is subject to change without notice.
October 2003
rev
P2811/12/14
AC Electrical Characteristics
3.3 V, 25° C
Symbol
fIN
fOUT
Parameter
Min
10
10
20
40
Typ
–
–
–
–
Max
40
40
80
160
Unit
MHz
MHz
MHz
MHz
Input frequency P2811/12/14
Output frequency P2811
Output frequency P2812
Output frequency P2814
Output rise time (measured at
1
tLH
0.69
0.66
ns
ns
0.8V to 2.0V)
Output fall time (measured at
2.0V to 0.8V)
1
tHL
tJC
tD
Jitter (cycle to cycle)
Output duty cycle
-200
45
–
50
200
55
ps
%
1. tLH and tHL are measured into a capacitive load of 15 pF
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Notice: The information in this document is subject to change without notice.
October 2003
P2811/12/14
rev
Package Information
Mechanical Package Outline 8-Pin SOIC
Dimensions in inches
Dimensions in millimeters
Symbol
Min
Nor
0.064
0.007
0.061
0.016
0.006
0.194
0.156
0.050 BSC
0.236
0.020
5°
Max
0.071
0.010
0.069
0.020
0.01
Min
1.45
0.10
1.35
0.31
0.10
4.72
3.75
Nor
1.63
Max
1.80
0.25
1.75
0.51
0.25
5.12
4.15
A
A1
A2
B
0.057
0.004
0.053
0.012
0.004
0.186
0.148
0.18
1.55
0.41
C
D
E
0.15
0.202
0.164
4.92
3.95
e
1.27 BSC
6.00
H
L
0.224
0.012
0°
0.248
0.028
8°
5.70
0.30
0°
6.30
0.70
8°
0.50
a
5°
Note: Controlling dimensions are millimeters
SOIC – 0.074 grams unit weight
Low Power EMI Reduction IC
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Notice: The information in this document is subject to change without notice.
October 2003
rev
P2811/12/14
Mechanical Package Outline 8-Pin TSSOP
Dimensions in inches
Dimensions in millimeters
Symbol
Min
Nor
Max
Min
Nor
Max
1.10
0.15
1.05
0.30
0.20
3.10
4.50
A
A1
A2
B
0.047
0.006
0.041
0.012
0.008
0.122
0.177
0.002
0.031
0.007
0.004
0.114
0.169
0.05
0.80
0.19
0.09
2.90
4.30
0.039
1.00
C
D
E
0.118
0.173
3.00
4.40
e
0.026 BSC
0.252
0.65 BSC
6.40
H
L
0.244
0.018
0°
0.260
0.030
8°
6.20
0.45
0°
6.60
0.75
8°
0.024
0.60
5°
5°
a
Note: Controlling dimensions are millimeters
TSSOP – 0.034 grams unit weight
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Notice: The information in this document is subject to change without notice.
October 2003
P2811/12/14
rev
Ordering Codes
Part Number
Marking
P2811A
P2812A
P2814A
P2811A
P2812A
P2814A
P2811A
P2812A
P2814A
P2811A
P2812A
P2814A
Package Type
8-pin SOIC, tube
Qty per reel
Temperature
0 to 70
0 to 70
0 to 70
0 to 70
0 to 70
0 to 70
0 to 70
0 to 70
0 to 70
0 to 70
0 to 70
0 to 70
P2811A-08ST
P2812A-08ST
P2814A-08ST
P2811A-08SR
P2812A-08SR
P2814A-08SR
P2811A-08TT
P2812A-08TT
P2814A-08TT
P2811A-08TR
P2812A-08TR
P2814A-08TR
8-pin SOIC, tube
8-pin SOIC, tube
8-pin SOIC, tape reel
8-pin SOIC, tape reel
8-pin SOIC, tape reel
8-pin TSSOP, tube
8-pin TSSOP, tube
8-pin TSSOP, tube
8-pin TSSOP, tape reel
8-pin TSSOP, tape reel
8-pin TSSOP, tape reel
2,500
2,500
2,500
2,500
2,500
2,500
Device Ordering Information
X 2 8 X X
X - 0 8 X X
Package:
ST – SOIC, TUBE
SR - SOIC, T/R
TT – TSSOP, TUBE
TR - TSSOP, T/R
Pin Count
F = Pb FREE
DEVICE NUMBER
Flow:
P = Commercial Temperature Range (0°C to 70°C)
I = Industrial Temperature Range (-25°C to 85°C)
A = Automotive Temperature Range (-40°C to 125°C)
Licensed under US patent Nos 5,488,627 and 5,631,920.
Preliminary datasheet. Specification subject to change without notice.
Low Power EMI Reduction IC
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Notice: The information in this document is subject to change without notice.
October 2003
rev
P2811/12/14
Alliance Semiconductor Corporation
2595, Augustine Drive,
Santa Clara, CA 95054
Tel# 408-855-4900
Copyright © Alliance Semiconductor
All Rights Reserved
Preliminary Information
Part Number: P2811/12/14
Document Version:
Fax: 408-855-4999
www.alsc.com
© Copyright 2003 Alliance Semiconductor Corporation. All rights reserved. Our three-point logo, our name and Intelliwatt are
trademarks or registered trademarks of Alliance. All other brand and product names may be the trademarks of their
respective companies. Alliance reserves the right to make changes to this document and its products at any time without
notice. Alliance assumes no responsibility for any errors that may appear in this document. The data contained herein
represents Alliance's best data and/or estimates at the time of issuance. Alliance reserves the right to change or correct this
data at any time, without notice. If the product described herein is under development, significant changes to these
specifications are possible. The information in this product data sheet is intended to be general descriptive information for
potential customers and users, and is not intended to operate as, or provide, any guarantee or warrantee to any user or
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assumes all risk of such use and agrees to indemnify Alliance against all claims arising from such use.
Low Power EMI Reduction IC
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Notice: The information in this document is subject to change without notice.
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