ICS7151AMI-50LFT [ICSI]
Spread Spectrum Clock Generator; 扩频时钟发生器
| 型号： | ICS7151AMI-50LFT |
| 厂家： | 
INTEGRATED CIRCUIT SOLUTION INC |
| 描述： | Spread Spectrum Clock Generator |
| 文件： | 总8页 (文件大小：152K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
ICS7151A-50
Spread Spectrum Clock Generator
Description
Features
The ICS7151A-50 is a clock generator for EMI
(Electromagnetic Interference) reduction. Spectral
peaks are attenuated by modulating the system clock
frequency. Down or center spread profiles are
selectable. Down spread will not exceed the maximum
frequency of an unspread clock, and center spread
does not change the average operating frequency of
the system
• Operating voltage of 3.3 V 0.3 V
• Packaged in 8-pin SOIC
• Available in Pb (lead) free package
• Input frequency range of 16.5 to 33.4 MHz
• Output frequency ranges of 8.3 to 16.7 MHz
• Provides a spread spectrum clock output ( 0.5%,
1.5% center spread; -1.0%, -3.0% down spread)
ICS offers many other clocks for computers and
computer peripherals. Consult ICS when you need to
remove crystals and oscillators from your board.
• Multiplication rate of x1/2
• Advanced, low-power CMOS process
• Pin compatible with the Fujitsu MB88151-500
Block Diagram
VDD
2
S1:0
PLL Clock
Synthesis
and Spread
Spectrum
Circuitry
ENS
CKOUT
XIN
Clock Buffer/
Crystal
Ocsillator
XOUT
External caps required with crystal for
accurate tuning of the clock
GND
MDS 7151A-50 A
1
Revision 102005
Integrated Circuit Systems, Inc. ● 525 Race Street, San Jose, CA 95126 ● tel (408) 297-1201 ● www.icst.com
ICS7151A-50
Spread Spectrum Clock Generator
Pin Assignment
Spread Direction and Percentage
Select Table
8
7
6
5
XOUT
VDD
XIN
GND
S0
1
2
3
4
S1
Pin 4
S0
Pin 3
Spread
Direction
Spread
Percentage (%)
0
0
1
1
0
1
0
1
Center
Center
Down
Down
±1.5
±0.5
-1.0
-3.0
ENS
S1
CKOUT
8 pin (150 mil) SOIC
ENS
Modulation
(note 1)
No Modulation
Modulation
0
1
Notes:
1. Pin 1 has a pull-up resistor.
Pin Descriptions
Pin
Pin
Pin Type
Pin Description
Number
Name
1
2
3
4
5
6
7
8
XIN
GND
S0
Input
Crystal pin/clock input pin.
Power Connect to ground.
Input
Input
Select pin 0. Spread modulation select.
Select pin 1. Spread modulation select.
S1
CKOUT
ENS
VDD
XOUT
Output Clock output.
Input
Modulation enable. Internal pull-up resistor.
Power Connect to +3.3 V.
Output Crystal connection pin.
MDS 7151A-50 A
2
Revision 102005
Integrated Circuit Systems, Inc. ● 525 Race Street, San Jose, CA 95126 ● tel (408) 297-1201 ● www.icst.com
ICS7151A-50
Spread Spectrum Clock Generator
traces just underneath the device, or on layers adjacent
to the ground plane layer used by the device.
External Components
The ICS7151A-50 requires a minimum number of
external components for proper operation.
Crystal Information
Decoupling Capacitor
The crystal used should be a fundamental mode (do
not use third overtone), parallel resonant. Crystal
capacitors should be connected from pins X1 to ground
and X2 to ground to optimize the initial accuracy. The
value of these capacitors is given by the following
equation:
A decoupling capacitor of 0.01µF must be connected
between GND and VDD on pins 2 and 7, as close to
these pins as possible. For optimum device
performance, the decoupling capacitor should be
mounted on the component side of the PCB. Avoid the
use of vias in the decoupling circuit.
Crystal caps (pF) = (C - 6) x 2
L
Series Termination Resistor
In the equation, C is the crystal load capacitance. So,
for a crystal with a 16 pF load capacitance, two 20 pF
[(16-6) x 2] capacitors should be used.
L
Series termination should be used on the clock output.
To series terminate a 50Ω trace (a commonly used
trace impedance) place a 27Ω resistor in series with
the clock line, as close to the clock output pin as
possible. The nominal impedance of the clock output is
25Ω.
Spread Spectrum Profile
The ICS7151A-50 low EMI clock generator uses a
triangular frequency modulation profile for optimal
down stream tracking of zero delay buffers and other
PLL devices. The frequency modulation amplitude is
constant with variations of the input frequency.
PCB Layout Recommendations
For optimum device performance and lowest output
phase noise, the following guidelines should be
observed.
1) The 0.01µF decoupling capacitor should be mounted
on the component side of the board as close to the
VDD pin as possible. No vias should be used between
the decoupling capacitor and VDD pin. The PCB trace
to VDD pin should be kept as short as possible, as
should the PCB trace to the ground via.
Modulation Rate
2) To minimize EMI, the 27Ω series termination resistor
(if needed) should be placed close to the clock output.
3) An optimum layout is one with all components on the
same side of the board, minimizing vias through other
signal layers. Other signal traces should be routed
away from the ICS7151A-50. This includes signal
Time
MDS 7151A-50 A
3
Revision 102005
Integrated Circuit Systems, Inc. ● 525 Race Street, San Jose, CA 95126 ● tel (408) 297-1201 ● www.icst.com
ICS7151A-50
Spread Spectrum Clock Generator
Absolute Maximum Ratings
Stresses above the ratings listed below can cause permanent damage to the ICS7151A-50. These ratings,
which are standard values for ICS commercially rated parts, are stress ratings only. Functional operation of
the device at these or any other conditions above those indicated in the operational sections of the
specifications is not implied. Exposure to absolute maximum rating conditions for extended periods can
affect product reliability. Electrical parameters are guaranteed only over the recommended operating
temperature range.
Item
Rating
Supply Voltage, VDD
-0.5 to 4.0 V
All Inputs and Outputs (referenced to GND)
Ambient Operating Temperature
Storage Temperature
-0.5 V to VDD+0.5 V
-40 to +85°C
-55 to +125°C
-40 to +125°C
260°C
Junction Temperature
Soldering Temperature
Overshoot (V
)
VDD + 1.0 V (t < 50 ns)
OVER
IOVER
Undershoot (V
)
GND - 1.0 V (t
< 50 ns)
IUNDER
UNDER
Overshoot/Undershoot
tUNDER < 50 ns
VIOVER < VDD + 1.0 V
VDD
Input pin
GND
VIUNDER < GND - 1.0 V
tOVER < 50 ns
Recommended Operation Conditions
Parameter
Min.
-40
Typ.
Max.
+85
3.6
Units
°C
Ambient Operating Temperature
Power Supply Voltage (measured in respect to GND)
+3.0
3.3
V
MDS 7151A-50 A
4
Revision 102005
Integrated Circuit Systems, Inc. ● 525 Race Street, San Jose, CA 95126 ● tel (408) 297-1201 ● www.icst.com
ICS7151A-50
Spread Spectrum Clock Generator
DC Electrical Characteristics
Unless stated otherwise, VDD = 3.3 V 0.3 V, Ambient Temperature -40 to +85°C
Parameter
Operating Voltage
Supply Current
Symbol
VDD
Conditions
Min.
Typ.
3.3
Max.
3.6
Units
V
3.0
IDD
No load, at 3.3 V,
output = 24 MHz
10
14
mA
Input Frequency
16.5
VDD * 0.8
0.0
33.4
MHz
V
Input High Voltage
Input Low Voltage
Output High Voltage
Output Low Voltage
Input Capacitance
V
XIN, S0, S1, ENS
XIN, S0, S1, ENS
VDD + 0.3
VDD * 0.20
IH
V
V
IL
V
CKOUT, I = -4 mA
2.0
V
OH
OH
V
CKOUT, I = 4 mA
0.4
16
15
V
OL
OL
C
XIN, S0, S1, ENS
pF
pF
IN
CKOUT, 8.3 to 66.7
MHz
CKOUT, 66.7 to 100
MHz
10
7
pF
pF
kΩ
Load Capacitance
C
L
CKOUT, 100 to 133.4
MHz
Input Pull-up Resistor
R
ENS
100
240
400
PU
AC Electrical Characteristics
Unless stated otherwise, VDD = 3.3 V 0.3 V, Ambient Temperature -40 to +85° C
Parameter
Symbol
Conditions
Min.
Typ.
Max. Units
Oscillation Frequency
f
Fundamental
16.5
33.4
MHz
X
oscillation
Input Frequency
f
XIN
16.5
8.3
33.4
16.7
MHz
MHz
IN
CKOUT, 2-frequency
division
Output Frequency
f
OUT
Input Clock Duty Cycle
Output Clock Duty Cycle
Output Slew Rate
XIN, 16.5 to 33.4 MHz
CKOUT, 1.5 V
40
40
50
60
60
%
%
t
DCC
CKOUT, 0.4 to 2.4 V,
load capacitance 15 pF
0.5
TBD
TBD
3.0
V/ns
No load, standard
deviation
200
5
ps
Cycle to Cycle Jitter
t
t
JC
Lock Time
CKOUT
2
ms
LK
Modulation Frequency
f
CKOUT=TBD
33
kHz
MOD
MDS 7151A-50 A
5
Revision 102005
Integrated Circuit Systems, Inc. ● 525 Race Street, San Jose, CA 95126 ● tel (408) 297-1201 ● www.icst.com
ICS7151A-50
Spread Spectrum Clock Generator
Input Frequency (fIN = 1/tIN)
tIN
0.8 VDD
CKIN
Output Slew Rate
2.4 V
0.4 V
CKOUT
tr
tf
SR = (2.4 - 0.4) /tr, SR = (2.4 - 0.4) /tf
Thermal Characteristics
Parameter
Symbol
Conditions
Min.
Typ. Max. Units
Thermal Resistance Junction to
Ambient
θ
θ
θ
θ
Still air
150
140
120
40
°C/W
°C/W
°C/W
°C/W
JA
JA
JA
JC
1 m/s air flow
3 m/s air flow
Thermal Resistance Junction to Case
MDS 7151A-50 A
6
Revision 102005
Integrated Circuit Systems, Inc. ● 525 Race Street, San Jose, CA 95126 ● tel (408) 297-1201 ● www.icst.com
ICS7151A-50
Spread Spectrum Clock Generator
Package Outline and Package Dimensions (8-pin SOIC, 150 Mil. Body)
Package dimensions are kept current with JEDEC Publication No. 95
Millimeters
Inches*
8
Symbol
A
Min
Max
1.75
0.25
0.51
0.25
5.00
4.00
Min
Max
1.35
0.10
0.33
0.19
4.80
3.80
.0532
.0040
.013
.0688
.0098
.020
A1
B
C
D
E
e
E
H
INDEX
AREA
.0075
.1890
.1497
.0098
.1968
.1574
1.27 BASIC
0.050 BASIC
1
2
H
h
5.80
0.25
0.40
0°
6.20
.2284
.010
.016
0°
.2440
.020
.050
8°
0.50
1.27
8°
D
L
α
*For reference only. Controlling dimensions in mm.
A
h x 45
A1
C
- C -
e
SEATING
PLANE
B
L
.10 (.004)
C
Ordering Information
Part / Order Number
ICS7151AM-50
ICS7151AM-50T
ICS7151AM-50LF
ICS7151AM-50LFT
ICS7151AMI-50
ICS7151AMI-50T
ICS7151AMI-50LF
ICS7151AMI-50LFT
Marking
7151AM50
7151AM50
151AM50L
151AM50L
151AMI50
151AMI50
51AMI50L
51AMI50L
Shipping Packaging
Tubes
Package
8-pin SOIC
8-pin SOIC
8-pin SOIC
8-pin SOIC
8-pin SOIC
8-pin SOIC
8-pin SOIC
8-pin SOIC
Temperature
0 to +70° C
0 to +70° C
0 to +70° C
0 to +70° C
-40 to +85° C
-40 to +85° C
-40 to +85° C
-40 to +85° C
Tape and Reel
Tubes
Tape and Reel
Tubes
Tape and Reel
Tubes
Tape and Reel
Parts that are ordered with a "LF" suffix to the part number are the Pb-Free configuration and are RoHS compliant.
While the information presented herein has been checked for both accuracy and reliability, Integrated Circuit Systems (ICS)
assumes no responsibility for either its use or for the infringement of any patents or other rights of third parties, which would
result from its use. No other circuits, patents, or licenses are implied. This product is intended for use in normal commercial
applications. Any other applications such as those requiring extended temperature range, high reliability, or other extraordinary
environmental requirements are not recommended without additional processing by ICS. ICS reserves the right to change any
circuitry or specifications without notice. ICS does not authorize or warrant any ICS product for use in life support devices or
critical medical instruments.
MDS 7151A-50 A
7
Revision 102005
Integrated Circuit Systems, Inc. ● 525 Race Street, San Jose, CA 95126 ● tel (408) 297-1201 ● www.icst.com
ICS7151A-50
Spread Spectrum Clock Generator
Revision History
Rev. Originator
Date
Description of Change
A
J. Sarma
10/20/05 Rev A; new device/datasheet.
MDS 7151A-50 A
8
Revision 102005
Integrated Circuit Systems, Inc. ● 525 Race Street, San Jose, CA 95126 ● tel (408) 297-1201 ● www.icst.com
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