IDT ICS844020-45

PRELIMINARY
ICS844020-45
FEMTOCLOCK™ CRYSTAL-TO-LVDS/
LVCMOS FREQUENCY SYNTHESIZER
GENERAL DESCRIPTION
FEATURES
• Sixteen differential LVDS outputs at 125MHz
One differential LVDS output at 156.25MHz
One LVCMOS/LVTTL single-ended output at 125MHz
One LVCMOS/LVTTL single-ended output at 25MHz
One LVCMOS/LVTTL single-ended output at 3.90625MHz
The ICS844020-45 is a 20 output synthesizer
HiPerClockS™ optimized to generate Gigabit and 10 Gigabit
Ether net clocks and is a member of the
HiPerClockS™ family of high performance clock
solutions from ICS. Using a 25MHz 18pF parallel
resonant crystal, the device will generate 156.25, 125MHz,
25MHz and 3.90625MHz clocks with mixed LVDS and LVTTL
output logic. The ICS844020-45 uses ICS’ 3rd generation low
phase noise VCO technology and can achieve <1ps typical rms
phase jitter, easily meeting Ethernet jitter requirements. The
ICS844020-45 is packaged in a 64-pin TQFP package with
exposed pad for optimum thermal performance.
ICS
• Crystal oscillator interface
• VCO range: 490MHz - 680MHz
• RMS phase jitter @ 125MHz, using a 25MHz crystal
(1.875MHz - 20MHz): 0.4ps (typical)
• RMS phase jitter @ 156.25MHz, using a 25MHz crystal
(1.875MHz - 20MHz): 0.37ps (typical)
• Full 2.5V operating supply
• 0°C to 70°C ambient operating temperature
• Available in both standard and lead-free RoHS-compliant
packages
VDDA
GND
Q19
VDDO
Q18
Q17
GND
nQ16
Q16
VDD
nQ15
Q15
GND
XTAL_IN
XTAL_OUT
GND
PIN ASSIGNMENT
64 63 62 61 60 59 58 57 56 55 54 53 52 51 50 49
1
2
3
4
5
6
7
8
9
10
11
12
13
14
ICS844020-45
64-Lead TQFP, EPAD
10mm x 10mm x 1.0mm
package body
Y package
Top View
15
16
17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32
48
47
46
45
44
43
42
41
40
39
38
37
36
35
34
33
VDD
Q5
nQ5
GND
Q6
nQ6
VDD
Q7
nQ7
GND
Q8
nQ8
VDD
Q9
nQ9
GND
GND
Q0
nQ0
VDD
Q1
nQ1
GND
Q2
nQ2
VDD
Q3
nQ3
GND
Q4
nQ4
VDD
GND
nQ14
Q14
VDD
nQ13
Q13
GND
nQ12
Q12
VDD
nQ11
Q11
GND
nQ10
125MHz
Q0
Q10
VDD
nQ0
BLOCK DIAGRAM
÷5
25MHz
XTAL_IN
OSC
Q15
nQ15
Phase
Detector
VCO
490-680MHz
Q17
XTAL_OUT
156.25MHz
nQ16
÷4
Q16
÷25
3.90625MHz
÷160
Q18
25MHz
Q19
The Preliminary Information presented herein represents a product in prototyping or pre-production. The noted characteristics are based on initial product
characterization. Integrated Circuit Systems, Incorporated (ICS) reserves the right to change any circuitry or specifications without notice.
IDT ™ / ICS™ LVDS/LVCMOS FREQUENCY SYNTHESIZER
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ICS844020-45 REV A JUNE 14, 2006
ICS844020-45
FEMTOCLOCK™ CRYSTAL-TO-LVDS/LVCMOS FREQUENCY SYNTHESIZER
PRELIMINARY
TABLE 1. PIN DESCRIPTIONS
Number
1, 7, 13, 20, 26,
32, 36, 42, 48,
50, 56, 61, 62
2, 3
5, 6
8, 9
11, 12
14, 15
18, 19
21, 22
24, 25
27, 28
30, 31
34, 35
37, 38
40, 41
43, 44
46, 47
51, 52
54, 55
4, 10, 16, 17,
23, 29, 33, 39,
45, 53
49
GND
Power
Power supply ground.
Q0, nQ0
Q1, nQ1
Q2, nQ2
Q3, nQ3
Q4, nQ4
Q5, nQ5
Q6, nQ6
Q7, nQ7
Q8, nQ8
Q9, nQ9
Q10, nQ10
Q11, nQ11
Q12, nQ12
Q13, nQ13
Q14, nQ14
Q15, nQ15
Q16, nQ16
Output
Differential clock output pair. LVPECL interface levels.
VDD
Power
Core power supply pins.
VDDA
Power
Analog supply pin.
57, 58, 60
Q17, Q18, Q19
Output
Single-Ended clock outputs. LVCMOS/LVTTL interface levels.
59
VDDO
XTAL_OUT,
XTAL_IN
Power
Output power supply pin for LVCMOS outputs.
Cr ystal oscillator interface. XTAL_OUT is the output.
XTAL_IN is the input.
63, 64
Name
Type
Input
Description
TABLE 2. PIN CHARACTERISTICS
Symbol
Parameter
CIN
Input Capacitance
CPD
Power Dissipation Capacitance
ROUT
Output Impedance
IDT ™ / ICS™ LVDS/LVCMOS FREQUENCY SYNTHESIZER
Test Conditions
Minimum
5
2
Typical
Maximum
Units
4
pF
TBD
pF
7
12
Ω
ICS844020-45 REV A JUNE 14, 2006
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FEMTOCLOCK™ CRYSTAL-TO-LVDS/LVCMOS FREQUENCY SYNTHESIZER
PRELIMINARY
ABSOLUTE MAXIMUM RATINGS
Supply Voltage, VDD
NOTE: Stresses beyond those listed under Absolute
Maximum Ratings may cause permanent damage
4.6V
Inputs, VI
-0.5V to VDD + 0.5V
Outputs, IO (LVCMOS)
-0.5V to VDD + 0.5V
to the device. These ratings are stress specifications only. Functional operation of product at
Outputs, IO (LVDS)
Continuous Current
Surge Current
these conditions or any conditions beyond those
listed in the DC Characteristics or AC Character-
10mA
15mA
istics is not implied. Exposure to absolute maximum rating conditions for extended periods may
affect product reliability.
Operating Temperature Range, TA -40°C to +85°C
Storage Temperature, TSTG
-65°C to 150°C
Package Thermal Impedance, θJA 22.3°C/W (0 lfpm)
TABLE 3A. POWER SUPPLY DC CHARACTERISTICS, VDD = VDDA = VDDO = 2.5V ± 5%,TA = 0°C TO 70°C
Symbol
VDD
Parameter
Core Supply Voltage
Test Conditions
Minimum
2.375
Typical
2.5
Maximum
2.625
Units
V
VDDA
Analog Supply Voltage
VDD – IDDA*10Ω
2.5
VDD
V
VDDO
Output Supply Voltage
2.375
2.5
2.625
V
IDD
Power Supply Current
TBD
mA
IDDA
IDDO
Analog Supply Current
Output Supply Current
TBD
TBD
mA
mA
TABLE 3B. LVCMOS/LVTTL DC CHARACTERISTICS, VDD = VDDA = VDDO = 2.5V ± 5%,TA = 0°C TO 70°C
Symbol Parameter
Test Conditions
VOH
Output High Voltage; NOTE 1
Q17:Q19
VDDO = 2.625V±5%
VOL
Output Low Voltage; NOTE 1
Q17:Q19
VDDO = 2.625V±5%
Minimum Typical
Maximum
1.8
Units
V
0.5
V
NOTE 1: Outputs terminated with 50Ω to VDDO/2. See Parameter Measurement Information,
Output Load Test Circuit diagram.
IDT ™ / ICS™ LVDS/LVCMOS FREQUENCY SYNTHESIZER
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FEMTOCLOCK™ CRYSTAL-TO-LVDS/LVCMOS FREQUENCY SYNTHESIZER
PRELIMINARY
TABLE 3C. LVDS DC CHARACTERISTICS, VDD = VDDA = 2.5V ± 5%,TA = 0°C TO 70°C
Symbol
Parameter
VOD
Differential Output Voltage
Test Conditions
Minimum
Typical
Maximum
Units
TBD
mV
∆ VOD
VOD Magnitude Change
TBD
mV
VOS
Offset Voltage
TBD
V
∆ VOS
VOS Magnitude Change
TBD
mV
TABLE 4. CRYSTAL CHARACTERISTICS
Parameter
Test Conditions
Minimum
Mode of Oscillation
Typical
Maximum
Units
Fundamental
Frequency
25
MHz
Ω
Equivalent Series Resistance (ESR)
50
Shunt Capacitance
7
pF
Drive Level
1
mW
Maximum
Units
NOTE: Characterized using an 18pF parallel resonant cr ystal.
TABLE 5. AC CHARACTERISTICS, VDD = VDDA = VDDO = 2.5V ± 5%,TA = 0°C TO 70°C
Symbol
fOUT
Parameter
Output
Frequency
Test Conditions
Minimum
Typical
Q0:15/nQ0:15
125
MHz
Q17
125
MHz
156.25
MHz
Q18
3.90625
MHz
Q19
25
MHz
Q16/nQ16
tsk(o)
Output Skew; NOTE 1, 2
tjit(Ø)
RMS Phase Jitter
(Random);
NOTE 3
t R / tF
Output
Rise/Fall Time
odc
Output
Duty Cycle
Q0:15/nQ0:15
Q16/nQ16
Q0:15/nQ0:15
125MHz, (1.875MHz - 20MHz)
156.25MHz,
(1.875MHz - 20MHz)
125MHz, 20% to 80%
156.25MHz, 20% to 80%
Q16:nQ16
Q0:15/nQ0:15
125MHz
TBD
ps
0.40
ps
0.37
ps
0.55
ns
200
ps
45
Q16/nQ16
156.25MHz
40
NOTE 1: Defined as skew between outputs at the same supply voltages and with equal load conditions.
Measured at VDDO/2.
NOTE 2: This parameter is defined in accordance with JEDEC Standard 65.
NOTE 3: Please refer to the Phase Noise Plots.
IDT ™ / ICS™ LVDS/LVCMOS FREQUENCY SYNTHESIZER
4
55
%
60
%
ICS844020-45 REV A JUNE 14, 2006
ICS844020-45
FEMTOCLOCK™ CRYSTAL-TO-LVDS/LVCMOS FREQUENCY SYNTHESIZER
PRELIMINARY
PARAMETER MEASUREMENT INFORMATION
1.25V±5%
1.25V±5%
2.5V±5%
POWER SUPPLY
Float GND
+
–
VDD,
VDDO VDDA
Qx
VDD,
VDDO
SCOPE
LVDS
SCOPE
VDDA
Qx
LVCMOS
nQx
GND
-1.25V±5%
2.5V LVDS OUTPUT LOAD AC TEST CIRCUIT
2.5V LVCMOS OUTPUT LOAD AC TEST CIRCUIT
nQx
V
DDO
Qx
Qx
2
nQy
V
DDO
Qy
Qy
2
t sk(o)
t sk(o)
LVDS OUTPUT SKEW
80%
LVCMOS OUTPUT SKEW
80%
80%
80%
VOD
Clock
Outputs
20%
20%
tR
Clock
Outputs
tF
LVDS OUTPUT RISE/FALL TIME
IDT ™ / ICS™ LVDS/LVCMOS FREQUENCY SYNTHESIZER
20%
20%
tR
tF
LVCMOS OUTPUT RISE/FALL TIME
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FEMTOCLOCK™ CRYSTAL-TO-LVDS/LVCMOS FREQUENCY SYNTHESIZER
PRELIMINARY
Phase Noise Plot
Noise Power
nQ0:nQ16
Q0:Q16
t PW
Phase Noise Mask
t
f1
Offset Frequency
odc =
f2
PERIOD
t PW
x 100%
t PERIOD
RMS Jitter = Area Under the Masked Phase Noise Plot
RMS PHASE JITTER
LVDS OUTPUT DUTY CYCLE/PULSE WIDTH/PERIOD
V
DDO
2
Q17:Q19
t PW
t
odc =
PERIOD
t PW
x 100%
t PERIOD
LVCMOS OUTPUT DUTY CYCLE/PULSE WIDTH/PERIOD
IDT ™ / ICS™ LVDS/LVCMOS FREQUENCY SYNTHESIZER
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FEMTOCLOCK™ CRYSTAL-TO-LVDS/LVCMOS FREQUENCY SYNTHESIZER
PRELIMINARY
TYPICAL PHASE NOISE AT 125MHZ (LVDS)
➤
0
-10
-20
Ethernet Filter
-30
125MHz
RMS Phase Jitter (Random)
1.875MHz to 20MHz = 0.40ps (typical)
-70
-80
-90
-100
-110
-120
-130
Raw Phase Noise Data
➤
NOISE POWER dBc
Hz
-40
-50
-60
➤
-140
-150
-160
-170
-180
-190
-200
Phase Noise Result by adding
Ethernet Filter to raw data
10
100
1k
10k
100k
1M
10M
100M
TYPICAL PHASE NOISE AT 156.25MHZ (LVDS)
➤
0
-10
-20
-30
-40
-50
-60
-70
-80
-90
Ethernet Filter
156.25MHz
RMS Phase Jitter (Random)
1.875MHz to 20MHz = 0.37ps (typical)
Raw Phase Noise Data
-100
-110
-120
➤
NOISE POWER dBc
Hz
OFFSET FREQUENCY (HZ)
-130
-140
-150
-160
-170
-180
-190
Phase Noise Result by adding
Ethernet Filter to raw data
➤
-200
10
100
1k
10k
100k
1M
10M
100M
OFFSET FREQUENCY (HZ)
IDT ™ / ICS™ LVDS/LVCMOS FREQUENCY SYNTHESIZER
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FEMTOCLOCK™ CRYSTAL-TO-LVDS/LVCMOS FREQUENCY SYNTHESIZER
PRELIMINARY
APPLICATION INFORMATION
POWER SUPPLY FILTERING TECHNIQUES
As in any high speed analog circuitry, the power supply pins
are vulnerable to random noise. The ICS844020-45 provides
separate power supplies to isolate any high switching noise
from the outputs to the internal PLL. VDD, VDDA, and VDDO should
be individually connected to the power supply plane through
vias, and bypass capacitors should be used for each pin. To
achieve optimum jitter performance, power supply isolation is
required. Figure 1 illustrates how a 10Ω resistor along with a
10µF and a .01µF bypass capacitor should be connected to
each VDDA.
2.5V
VDD
.01µF
10Ω
VDDA
.01µF
10µF
FIGURE 1. POWER SUPPLY FILTERING
CRYSTAL INPUT INTERFACE
were determined using a 25MHz, 18pF parallel resonant crystal
and were chosen to minimize the ppm error.
The ICS844020-45 has been characterized with 18pF parallel
resonant crystals. The capacitor values shown in Figure 2 below
XTAL_IN
C1
22p
X1
18pF Parallel Cry stal
XTAL_OUT
C2
22p
ICS84332
Figure 2. CRYSTAL INPUt INTERFACE
IDT ™ / ICS™ LVDS/LVCMOS FREQUENCY SYNTHESIZER
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FEMTOCLOCK™ CRYSTAL-TO-LVDS/LVCMOS FREQUENCY SYNTHESIZER
PRELIMINARY
LVCMOS TO XTAL INTERFACE
The XTAL_IN input can accept a single-ended LVCMOS
signal through an AC couple capacitor. A general interface diagram
is shown in Figure 3. The XTAL_OUT pin can
be left floating. The input edge rate can be as slow as
10ns. For LVCMOS inputs, it is recommended that the
amplitude be reduced from full swing to half swing in order
to prevent signal interference with the power rail and to
reduce noise. This configuration requires that the output
impedance of the driver (Ro) plus the series resistance
(Rs) equals the transmission line impedance. In addition, matched
termination at the crystal input will attenuate the signal in half.
This can be done in one of two ways. First, R1 and R2 in parallel
should equal the transmission line impedance. For most 50Ω
applications, R1 and R2 can be 100Ω. This can also be
accomplished by removing R1 and making R2 50Ω.
VDD
VDD
R1
Ro
.1uf
Rs
Zo = 50
Zo = Ro + Rs
XTAL_IN
R2
XTAL_OUT
Figure 3. GENERAL DIAGRAM FOR LVCMOS DRIVER
TO
XTAL INPUT INTERFACE
RECOMMENDATIONS FOR UNUSED OUTPUT PINS
OUTPUTS:
LVCMOS OUTPUT:
All unused LVCMOS output can be left floating. There should
be no trace attached.
LVDS OUTPUT
All unused LVDS output pairs can be either left floating or
terminated with 100Ω across. If they are left floating, there
should be no trace attached.
IDT ™ / ICS™ LVDS/LVCMOS FREQUENCY SYNTHESIZER
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ICS844020-45 REV A JUNE 14, 2006
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FEMTOCLOCK™ CRYSTAL-TO-LVDS/LVCMOS FREQUENCY SYNTHESIZER
PRELIMINARY
2.5V LVDS DRIVER TERMINATION
transmission line environment. For buffer with multiple LDVS
driver, it is recommended to terminate the unused outputs.
Figure 4 shows a typical termination for LVDS driver in
characteristic impedance of 100Ω differential (50Ω single)
2.5V
2.5V
LVDS_Driv er
+
R1
100
-
100 Ohm
Differential
Line
Ω
100Ω
Differential Transmission
Transmission Line
FIGURE 4. TYPICAL LVDS DRIVER TERMINATION
THERMAL RELEASE PATH
contacted through solder as shown in Figure 5. For further
information, please refer to the Application Note on Surface
Mount Assembly of Amkor’s Thermally /Electrically Enhance
Leadframe Base Package, Amkor Technology.
The expose metal pad provides heat transfer from the device
to the P.C. board. The expose metal pad is ground pad
connected to ground plane through thermal via. The exposed
pad on the device to the exposed metal pad on the PCB is
EXPOSED PAD
SOLDER M ASK
SOLDER
SIGNAL
TRACE
SIGNAL
TRACE
GROUND PLANE
Expose Metal Pad
THERM AL VIA
FIGURE 5. P.C. BOARD
FOR
IDT ™ / ICS™ LVDS/LVCMOS FREQUENCY SYNTHESIZER
(GROUND PAD)
EXPOSED PAD THERMAL RELEASE PATH EXAMPLE
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FEMTOCLOCK™ CRYSTAL-TO-LVDS/LVCMOS FREQUENCY SYNTHESIZER
PRELIMINARY
RELIABILITY INFORMATION
TABLE 6. θJAVS. AIR FLOW TABLE
FOR
64 LEAD TQFP, E-PAD
θJA by Velocity (Linear Feet per Minute)
Multi-Layer PCB, JEDEC Standard Test Boards
0
200
500
22.3°C/W
17.2°C/W
15.1°C/W
TRANSISTOR COUNT
The transistor count for ICS844020-45 is: 1782
The ICS logo is a registered trademark, and HiPerClockS and FEMTOCLOCKS are trademarks of Integrated Circuit Systems, Inc. All other trademarks are the property of their respective
owners and may be registered in certain jurisdictions.
IDT ™ / ICS™ LVDS/LVCMOS FREQUENCY SYNTHESIZER
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FEMTOCLOCK™ CRYSTAL-TO-LVDS/LVCMOS FREQUENCY SYNTHESIZER
PRELIMINARY
TABLE 8. ORDERING INFORMATION
Part/Order Number
Marking
Package
Shipping Packaging
Temperature
ICS844020AY-45
ICS844020AY-45
64 Lead TQFP, E-Pad
Tray
0°C to 70°C
ICS844020AY-45T
ICS844020AY-45
64 Lead TQFP, E-Pad
500 Tape & Reel
0°C to 70°C
ICS844020AY-45LF
TBD
64 Lead "Lead-Free" TQFP, E-Pad
Tray
0°C to 70°C
ICS844020AY-45LFT
TBD
64 Lead "Lead-Free" TQFP, E-Pad
500 Tape & Reel
0°C to 70°C
NOTE: Par ts that are ordered with an "LF" suffix to the par t number are the Pb-Free configuration and are RoHS compliant.
The ICS logo is a registered trademark, and HiPerClockS and FEMTOCLOCKS are trademarks of Integrated Circuit Systems, Inc. All other trademarks are the property of their respective owners and
may be registered in certain jurisdictions.
While the information presented herein has been checked for both accuracy and reliability, Integrated Circuit Systems, Incorporated (ICS) assumes no responsibility for either its use or for 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.
IDT ™ / ICS™ LVDS/LVCMOS FREQUENCY SYNTHESIZER
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ICS844020-45 REV A JUNE 14, 2006
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FEMTOCLOCK™ CRYSTAL-TO-LVDS/LVCMOS FREQUENCY SYNTHESIZER
PRELIMINARY
Innovate with IDT and accelerate your future networks. Contact:
www.IDT.com
For Sales
For Tech Support
800-345-7015
408-284-8200
Fax: 408-284-2775
[email protected]
480-763-2056
Corporate Headquarters
Asia Pacific and Japan
Europe
Integrated Device Technology, Inc.
6024 Silver Creek Valley Road
San Jose, CA 95138
United States
800 345 7015
+408 284 8200 (outside U.S.)
Integrated Device Technology
Singapore (1997) Pte. Ltd.
Reg. No. 199707558G
435 Orchard Road
#20-03 Wisma Atria
Singapore 238877
+65 6 887 5505
IDT Europe, Limited
321 Kingston Road
Leatherhead, Surrey
KT22 7TU
England
+44 (0) 1372 363 339
Fax: +44 (0) 1372 378851
© 2006 Integrated Device Technology, Inc. All rights reserved. Product specifications subject to change without notice. IDT and the IDT logo are trademarks of Integrated Device
Technology, Inc. Accelerated Thinking is a service mark of Integrated Device Technology, Inc. All other brands, product names and marks are or may be trademarks or registered
trademarks used to identify products or services of their respective owners.
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