ICST ICS7151 Spread spectrum clock generator Datasheet

ICS7151
Spread Spectrum Clock Generator
Description
Features
The ICS7151-10, -20, -40, and -50 are clock
generators for EMI (Electro Magnetic Interference)
reduction (see below for frequency ranges and
multiplier ratios). Spectral peaks can be attenuated by
slightly modulating the oscillation frequency. Both down
and center spread profiles are selectable. Down spread
maintains an average frequency less than an unspread
clock, and will not exceed the maximum frequency of
an unspread clock.
•
•
•
•
•
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, 16.5 to
33.4 MHz, 33.3 to 66.7 MHz, 66.6 to 133.4 MHz
• Provides a spread spectrum clock output (±0.5%,
±1.5% center spread; -1.0%, -3.0% down spread)
• Multiplication rates of x1/2, x1, x2, and x4
• Advanced, low-power CMOS process
Block Diagram
VDD
S1:0
2
PLL Clock
Synthesis
and Spread
Spectrum
Circuitry
ENS
XIN
CKOUT
Clock Buffer/
Crystal
Ocsillator
XOUT
GND
External caps required with crystal for
accurate tuning of the clock
Product Lineup
Product
Input Frequency Range
Multiplier Ratio
Output Frequency Range
ICS7151M-10, ICS7151MI-10
16.5 MHz to 33.4 MHz
X1
16.5 MHz to 33.4 MHz
ICS7151M-20, ICS7151MI-20
16.5 MHz to 33.4 MHz
X2
33.3 MHz to 66.7 MHz
ICS7151M-40, ICS7151MI-40
16.5 MHz to 33.4 MHz
X4
66.6 MHz to 133.4 MHz
ICS7151M-50, ICS7151MI-50
16.5 MHz to 33.4 MHz
X1/2
8.3 MHz to 16.7 MHz
1
MDS 7151 E
Integrated Circuit Systems, Inc.
●
525 Race Street, San Jose, CA 95126
Revision 012306
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tel (408) 297-1201
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ICS7151
Spread Spectrum Clock Generator
Pin Assignment
Spread Direction and Percentage
Select Table
XIN
1
8
XOUT
GND
2
7
VDD
S0
3
6
ENS
S1
4
5
CKOUT
S1
Pin 4
(note1)
S0
Pin 3
(note1)
Spread
Direction
Spread
Percentage (%)
0
0
Center
±1.5
0
1
Center
±0.5
1
0
Down
-1.0
1
1
Down
-3.0
8 pin (150 mil) SOIC
ENS
(note 2)
Spread Spectrum
0
OFF
1
ON
Notes:
1. The modulation rate varies with input frequency.
2. Spread will default to ON when ENS pin is left open.
Pin Descriptions
Pin
Number
Pin
Name
Pin Type
1
XIN
Input
Resonator connection pin/clock input pin.
2
GND
Power
Connect to ground.
3
S0
Input
Select pin 0. Modulation rate setting pin.
4
S1
Input
Select pin 1. Modulation rate setting pin.
5
CKOUT
Output
6
ENS
Input
Modulation enable setting pin. Internal pull-up resistor.
7
VDD
Power
Connect to +3.3 V.
8
XOUT
Output
Resonator connection pin.
Modulated clock output pin.
2
MDS 7151 E
Integrated Circuit Systems, Inc.
Pin Description
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525 Race Street, San Jose, CA 95126
Revision 012306
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ICS7151
Spread Spectrum Clock Generator
External Components
underneath the device, or on layers adjacent to the
ground plane layer used by the device.
Decoupling Capacitor
A decoupling capacitor of 0.01µF must be connected
between GND and VDD on pin 7, as close to this pin 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.
Series Termination Resistor
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.
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.
2) To minimize EMI, the 27Ω series termination resistor
(if needed) should be placed close to the clock output.
Crystal Information
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:
Crystal caps (pF) = (CL - 6) x 2
In the equation, CL 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.
Spread Spectrum Profile
The ICS7151 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.
Modulation Rate
Frequency
The ICS7151 requires a minimum number of external
components for proper operation.
Time
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 ICS7151. This includes signal traces just
3
MDS 7151 E
Integrated Circuit Systems, Inc.
●
525 Race Street, San Jose, CA 95126
Revision 012306
●
tel (408) 297-1201
●
www.icst.com
ICS7151
Spread Spectrum Clock Generator
Absolute Maximum Ratings
Stresses above the ratings listed below can cause permanent damage to the ICS7151. 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
7V
All Inputs and Outputs (referenced to GND)
-0.5 V to VDD+0.5 V
Ambient Operating Temperature
-40 to +85°C
Storage Temperature
-55 to +125°C
Junction Temperature
-40 to +125°C
Soldering Temperature
260°C
Overshoot (VIOVER)
VDD + 1.0 V (tOVER < 50 ns)
Undershoot (VIUNDER)
GND - 1.0 V (tUNDER < 50 ns)
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.
Ambient Operating Temperature
-40
Power Supply Voltage (measured in respect to GND)
+3.0
3.3
Max.
Units
+85
°C
3.6
V
4
MDS 7151 E
Integrated Circuit Systems, Inc.
Typ.
●
525 Race Street, San Jose, CA 95126
Revision 012306
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tel (408) 297-1201
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ICS7151
Spread Spectrum Clock Generator
DC 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
3.0
3.3
3.6
V
10
20
mA
Operating Voltage
VDD
Supply Current
IDD
No load, at 3.3 V
Input High Voltage
VIH
XIN, S0, S1, ENS
VDDx0.8
VDD + 0.3
V
Input Low Voltage
VIL
XIN, S0, S1, ENS
0.0
VDDx0.20
V
Output High Voltage
VOH
CKOUT, IOH = -4 mA
2.0
Output Low Voltage
VOL
CKOUT, IOL = 4 mA
0.4
V
Input Capacitance
CIN
XIN, S0, S1, ENS
16
pF
CKOUT, 8.3 to 66.7
MHz
15
pF
CKOUT, 66.7 to 100
MHz
10
pF
CKOUT, 100 to 133.4
MHz
7
pF
400
kΩ
Load Capacitance
CL
Input Pull-up Resistor
ENS
RPU
V
100
240
AC Electrical Characteristics
Unless stated otherwise, VDD = 3.3 V ±0.3 V, Ambient Temperature -40 to +85° C
Parameter
Symbol
Conditions
Min.
Max.
Units
16.5
33.4
MHz
16.5
33.4
MHz
CKOUT, Multiply by 1
(ICS7151-10)
16.5
33.4
MHz
CKOUT, Multiply by 2
(ICS7151-20)
33.3
66.7
MHz
CKOUT, Multiply by 4
(ICS7151-40)
66.6
133.4
MHz
CKOUT, 2-frequency
division (ICS7151-50)
8.3
16.7
MHz
XIN, 16.5 to 33.4 MHz
40
60
%
CKOUT, 1.5 V
40
60
%
CKOUT, 0.4 to 2.4 V,
CL = 15 pF
0.5
3.0
V/ns
Input Crystal Frequency
Input Clock Frequency
fIN
Output Frequency
fOUT
Input Clock Duty Cycle
Output Clock Duty Cycle
Output Slew Rate
50
5
MDS 7151 E
Integrated Circuit Systems, Inc.
tDCC
Typ.
●
525 Race Street, San Jose, CA 95126
Revision 012306
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ICS7151
Spread Spectrum Clock Generator
Parameter
Symbol
Cycle to Cycle Jitter
tJC
Power-up Time
Modulation Frequency
fMOD
Conditions
Min.
Typ.
Max.
Units
No load, spread off
(ICS7151-10, -20)
100
ps
No load, spread off
(ICS7151-40)
150
ps
No load, spread off
(ICS7151-50)
200
ps
5
ms
PLL lock-time from
power-up to 1% of final
value
2
CKOUT
33
kHz
Input Frequency (fIN = 1/tIN)
tIN
0.8 VDD
XIN
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 8 SOIC
Parameter
Symbol
Thermal Resistance Junction to
Ambient
Thermal Resistance Junction to Case
Min.
Typ.
Max. Units
θJA
Still air
150
°C/W
θJA
1 m/s air flow
140
°C/W
θJA
3 m/s air flow
120
°C/W
40
°C/W
θJC
6
MDS 7151 E
Integrated Circuit Systems, Inc.
Conditions
●
525 Race Street, San Jose, CA 95126
Revision 012306
●
tel (408) 297-1201
●
www.icst.com
ICS7151
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
8
Millimeters
Symbol
E
Min
A
A1
B
C
D
E
e
H
h
L
α
H
INDEX
AREA
1 2
D
A
Inches
Max
Min
1.35
1.75
0.10
0.25
0.33
0.51
0.19
0.25
4.80
5.00
3.80
4.00
1.27 BASIC
5.80
6.20
0.25
0.50
0.40
1.27
0°
8°
Max
.0532
.0688
.0040
.0098
.013
.020
.0075
.0098
.1890
.1968
.1497
.1574
0.050 BASIC
.2284
.2440
.010
.020
.016
.050
0°
8°
h x 45
A1
C
-Ce
SEATING
PLANE
B
L
.10 (.004)
7
MDS 7151 E
Integrated Circuit Systems, Inc.
C
●
525 Race Street, San Jose, CA 95126
Revision 012306
●
tel (408) 297-1201
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www.icst.com
ICS7151
Spread Spectrum Clock Generator
Ordering Information
Part / Order Number
Marking
Shipping Packaging
Package
Temperature
ICS7151M-10
ICS7151M-10T
ICS7151M-10LF
ICS7151M-10LFT
ICS7151M-20
ICS7151M-20T
ICS7151M-20LF
ICS7151M-20LFT
ICS7151M-40
ICS7151M-40T
ICS7151M-40LF
ICS7151M-40LFT
ICS7151M-50
ICS7151M-50T
ICS7151M-50LF
ICS7151M-50LFT
ICS7151MI-10
ICS7151MI-10T
ICS7151MI-10LF
ICS7151MI-10LFT
ICS7151MI-20
ICS7151MI-20T
ICS7151MI-20LF
ICS7151MI-20LFT
ICS7151MI-40
ICS7151MI-40T
ICS7151MI-40LF
ICS7151MI-40LFT
ICS7151MI-50
ICS7151MI-50T
ICS7151MI-50LF
ICS7151MI-50LFT
7151M-10
7151M-10
7151M10L
7151M10L
7151M-20
7151M-20
7151M20L
7151M20L
7151M-40
7151M-40
7151M40L
7151M40L
7151M-50
7151M-50
7151M50L
7151M50L
7151MI10
7151MI10
51MI10LF
51MI10LF
7151MI20
7151MI20
51MI20LF
51MI20LF
7151MI40
7151MI40
51MI40LF
51MI40LF
7151MI50
7151MI50
51MI50LF
51MI50LF
Tubes
Tape and Reel
Tubes
Tape and Reel
Tubes
Tape and Reel
Tubes
Tape and Reel
Tubes
Tape and Reel
Tubes
Tape and Reel
Tubes
Tape and Reel
Tubes
Tape and Reel
Tubes
Tape and Reel
Tubes
Tape and Reel
Tubes
Tape and Reel
Tubes
Tape and Reel
Tubes
Tape and Reel
Tubes
Tape and Reel
Tubes
Tape and Reel
Tubes
Tape and Reel
8-pin SOIC
8-pin SOIC
8-pin SOIC
8-pin SOIC
8-pin SOIC
8-pin SOIC
8-pin SOIC
8-pin SOIC
8-pin SOIC
8-pin SOIC
8-pin SOIC
8-pin SOIC
8-pin SOIC
8-pin SOIC
8-pin SOIC
8-pin SOIC
8-pin SOIC
8-pin SOIC
8-pin SOIC
8-pin SOIC
8-pin SOIC
8-pin SOIC
8-pin SOIC
8-pin SOIC
8-pin SOIC
8-pin SOIC
8-pin SOIC
8-pin SOIC
8-pin SOIC
8-pin SOIC
8-pin SOIC
8-pin SOIC
0 to +70° C
0 to +70° C
0 to +70° C
0 to +70° C
0 to +70° C
0 to +70° C
0 to +70° C
0 to +70° C
0 to +70° C
0 to +70° C
0 to +70° C
0 to +70° C
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
-40 to +85° C
-40 to +85° C
-40 to +85° C
-40 to +85° C
-40 to +85° C
-40 to +85° C
-40 to +85° C
-40 to +85° C
-40 to +85° C
-40 to +85° C
-40 to +85° C
-40 to +85° C
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.
8
MDS 7151 E
Integrated Circuit Systems, Inc.
●
525 Race Street, San Jose, CA 95126
Revision 012306
●
tel (408) 297-1201
●
www.icst.com
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