ICS ICS843051

ICS843051
Integrated
Circuit
Systems, Inc.
FEMTOCLOCKS™ CRYSTAL-TO3.3V LVPECL CLOCK GENERATOR
GENERAL DESCRIPTION
FEATURES
The ICS843051 is a Gb Ethernet Generator and a
member of the HiPerClocks TM family of high
HiPerClockS™
performance devices from ICS. The ICS843051 can
synthesize 10 Gigabit Ethernet, SONET, or Serial
ATA reference clock frequencies with the
appropriate choice of crystal and output divider. The ICS843051
has excellent phase jitter performance and is packaged in a
small 8-pin TSSOP, making it ideal for use in systems with
limited board space.
• 1 differential 3.3V LVPECL output
ICS
• Crystal oscillator interface designed for
18pF parallel resonant crystals
• RMS phase jitter at:
155.52MHz (12KHz - 20MHz): 0.74ps (typical)
156.25MHz (1.875MHz - 20MHz): 0.43ps (typical)
161.13MHz (1.933MHz - 20MHz): 0.43ps (typical)
• RMS phase noise at 156.25MHz
Offset
Noise Power
100Hz .................. -95 dBc/Hz
1KHz ................ -110 dBc/Hz
10KHz ................ -125 dBc/Hz
100KHz ................ -125 dBc/Hz
• 3.3V operating supply
• 0°C to 70°C ambient operating temperature
• Industrial temperature information available upon request
• Lead-Free package fully RoHS compliant
PIN ASSIGNMENT
FREQUENCY TABLE
Inputs
Crystal Frequency (MHz)
FREQ_SEL
Output Frequency
(MHz)
20.141601
0
161.132812
20.141601
1
80.566406
19.53125
0
156.25
19.53125
1
78.125
19.44
0
155.52
19.44
1
77.76
18.75
0
15 0
18.75
1
75
VCCA
VEE
XTAL_OUT
XTAL_IN
1
2
3
4
8
7
6
5
VCC
Q0
nQ0
FREQ_SEL
ICS843051
8-Lead TSSOP
4.40mm x 3.0mm x 0.925mm
package body
G Package
Top View
BLOCK DIAGRAM
FREQ_SEL
XTAL_IN
OSC
XTAL_OUT
Phase
Detector
0 ÷4 (default)
1 ÷8
VCO
nQ0
Q0
÷32
(fixed)
843051AG
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1
REV. A DECEMBER 14, 2004
ICS843051
Integrated
Circuit
Systems, Inc.
FEMTOCLOCKS™ CRYSTAL-TO3.3V LVPECL CLOCK GENERATOR
TABLE 1. PIN DESCRIPTIONS
Number
Name
Type
1
VCCA
Power
2
3,
4
5
V EE
XTAL_OUT,
XTAL_IN
FREQ_SEL
Power
6, 7
nQ0, Q0
Output
Differential clock outputs. LVPECL interface levels.
8
VCC
Power
Core supply pin.
Input
Input
Description
Analog supply pin.
Negative supply pin.
Crystal oscillator interface. XTAL_IN is the input,
XTAL_OUT is the output.
Pulldown Frequency select pin. LVCMOS/LVTTL interface levels.
NOTE: Pulldown refers to internal input resistors. See Table 2, Pin Characterristics, for typical values.
TABLE 2. PIN CHARACTERISTICS
Symbol
Parameter
CIN
Input Capacitance
4
pF
RPULLDOWN
Input Pulldown Resistor
51
KΩ
843051AG
Test Conditions
Minimum
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2
Typical
Maximum
Units
REV. A DECEMBER 14, 2004
ICS843051
Integrated
Circuit
Systems, Inc.
FEMTOCLOCKS™ CRYSTAL-TO3.3V LVPECL CLOCK GENERATOR
ABSOLUTE MAXIMUM RATINGS
Supply Voltage, VCC
4.6V
Inputs, VI
-0.5V to VCC + 0.5V
Outputs, IO
Continuous Current
Surge Current
50mA
100mA
Package Thermal Impedance, θJA
101.7°C/W (0 mps)
Storage Temperature, TSTG
-65°C to 150°C
NOTE: Stresses beyond those listed under Absolute
Maximum Ratings may cause permanent damage to the
device. These ratings are stress specifications only. Functional
operation of product at these conditions or any conditions beyond those listed in the DC Characteristics or AC Characteristics is not implied. Exposure to absolute maximum rating
conditions for extended periods may affect product reliability.
TABLE 3A. POWER SUPPLY DC CHARACTERISTICS, VCC = 3.3V±5%, TA=0°C TO 70°C
Symbol
Parameter
Minimum
Typical
Maximum
Units
VCC
Core Supply Voltage
Test Conditions
3.135
3.3
3.465
V
VCCA
Analog Supply Voltage
3.135
3.3
3.465
V
ICC
Power Supply Current
70
mA
ICCA
Analog Supply Current
15
mA
IEE
Power Supply Current
85
mA
Maximum
Units
VCC + 0.3
V
TABLE 3B. LVCMOS/LVTTL DC CHARACTERISTICS, VCC = 3.3V±5%, TA=0°C TO 70°C
Symbol
Parameter
Test Conditions
VIH
Input High Voltage
FREQ_SEL
Minimum
Typical
2
VIL
Input Low Voltage
FREQ_SEL
IIH
Input High Current
FREQ_SEL
VCC = VIN = 3.465V
IIL
Input Low Current
FREQ_SEL
VCC = 3.465V, VIN = 0V
-0.3
0.8
V
150
µA
-5
µA
TABLE 3C. LVPECL DC CHARACTERISTICS, VCC = 3.3V±5%, TA=0°C TO 70°C
Symbol
Parameter
Maximum
Units
VOH
Output High Voltage; NOTE 1
Test Conditions
Minimum
VCC - 1.4
Typical
VCC - 0.9
V
VOL
Output Low Voltage; NOTE 1
VCC - 2.0
VCC - 1.7
V
VSWING
Peak-to-Peak Output Voltage Swing
0.6
1.0
V
Maximum
Units
40
MHz
NOTE 1: Outputs terminated with 50Ω to VCC - 2V.
TABLE 4. CRYSTAL CHARACTERISTICS
Parameter
Test Conditions
Minimum
Mode of Oscillation
Typical
Fundamental
Frequency
12
Equivalent Series Resistance (ESR)
50
Ω
Shunt Capacitance
7
pF
843051AG
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REV. A DECEMBER 14, 2004
ICS843051
Integrated
Circuit
Systems, Inc.
FEMTOCLOCKS™ CRYSTAL-TO3.3V LVPECL CLOCK GENERATOR
TABLE 5. AC CHARACTERISTICS, VCC = 3.3V±5%, TA=0°C TO 70°C
Symbol
fOUT
tjit(Ø)
tR / tF
Parameter
Test Conditions
Output Frequency
RMS Phase Jitter (Random);
NOTE 1
Output Rise/Fall Time
155.52MHz @ Integration Range:
12KHz - 20MHz
156.25MHz @ Integration Range:
1.875MHz - 20MHz
156.25MHz @ Integration Range:
12KHz - 20MHz
161.13MHz @ Integration Range:
1.933MHz - 20MHz
161.13MHz @ Integration Range:
12KHz - 20MHz
20% to 80%
odc
Output Duty Cycle
NOTE 1: Please refer to the Phase Noise Plots following this section.
843051AG
Minimum
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4
Typical
Maximum
Units
155.52
MHz
156.25
MHz
161.13
MHz
0.74
ps
0.43
ps
0.75
ps
0.43
ps
0.72
ps
325
600
ps
49
51
%
REV. A DECEMBER 14, 2004
ICS843051
Integrated
Circuit
Systems, Inc.
FEMTOCLOCKS™ CRYSTAL-TO3.3V LVPECL CLOCK GENERATOR
TYPICAL PHASE NOISE AT 155.52MHZ
➤
0
-10
-20
Filter
-30
-40
-50
155.52MHz
RMS Phase Noise Jitter
12KHz to 20MHz = 0.74ps (typical)
-80
-90
-100
Raw Phase Noise Data
-110
-120
-130
➤
-140
➤
NOISE POWER dBc
Hz
-60
-70
-150
-160
Phase Noise Result by adding
a Filter to raw data
-170
-180
-190
100
1k
10k
100k
1M
10M
100M
OFFSET FREQUENCY (HZ)
TYPICAL PHASE NOISE AT 156.25MHZ
➤
0
-10
-20
Gb Ethernet Filter
-30
-40
-50
156.25MHz
RMS Phase Noise Jitter
1.875MHz to 20MHz = 0.43ps (typical)
-70
-80
-90
Raw Phase Noise Data
-100
-110
➤
NOISE POWER dBc
Hz
-60
-120
-130
-140
-150
-190
100
➤
-160
-170
-180
1k
Phase Noise Result by adding
Gb Ethernet Filter to raw data
10k
100k
1M
10M
100M
OFFSET FREQUENCY (HZ)
843051AG
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5
REV. A DECEMBER 14, 2004
ICS843051
Integrated
Circuit
Systems, Inc.
FEMTOCLOCKS™ CRYSTAL-TO3.3V LVPECL CLOCK GENERATOR
TYPICAL PHASE NOISE AT 161.13MHZ
➤
0
-10
-20
Filter
-50
161.13MHz
-60
-70
RMS Phase Noise Jitter
1.933M to 20MHz = 0.43ps (typical)
-80
-90
Raw Phase Noise Data
-100
-110
➤
NOISE POWER dBc
Hz
-30
-40
-120
-130
-140
-150
➤
-160
-170
-180
-190
100
Phase Noise Result by adding
a Filter to raw data
1k
10k
100k
1M
10M
100M
OFFSET FREQUENCY (HZ)
843051AG
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6
REV. A DECEMBER 14, 2004
ICS843051
Integrated
Circuit
Systems, Inc.
FEMTOCLOCKS™ CRYSTAL-TO3.3V LVPECL CLOCK GENERATOR
PARAMETER MEASUREMENT INFORMATION
2V
Phase Noise Plot
Qx
SCOPE
Noise Power
V CC
LVPECL
Phase Noise Mask
nQx
VEE
f1
Offset Frequency
f2
-1.3V ± 0.165V
RMS Jitter = Area Under the Masked Phase Noise Plot
3.3V OUTPUT LOAD AC TEST CIRCUIT
RMS PHASE JITTER
nQ0
80%
Q0
80%
VSW I N G
Pulse Width
t
odc =
Clock
Outputs
PERIOD
20%
20%
t PW
tR
tF
t PERIOD
OUTPUT DUTY CYCLE/PULSE WIDTH/PERIOD
843051AG
OUTPUT RISE/FALL TIME
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7
REV. A DECEMBER 14, 2004
ICS843051
Integrated
Circuit
Systems, Inc.
FEMTOCLOCKS™ CRYSTAL-TO3.3V LVPECL CLOCK GENERATOR
APPLICATION INFORMATION
POWER SUPPLY FILTERING TECHNIQUES
As in any high speed analog circuitry, the power supply pins
are vulnerable to random noise. The ICS843051 provides separate power supplies to isolate any high switching
noise from the outputs to the internal PLL. VCC, and VCCA 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 VCCA pin.
3.3V
VCC
.01µF
10Ω
V CCA
.01µF
10µF
FIGURE 1. POWER SUPPLY FILTERING
CRYSTAL INPUT INTERFACE
parallel resonant crystal and were chosen to minimize the ppm
error. The optimum C1 and C2 values can be slightly adjusted
for different board layouts.
The ICS843051 has been characterized with 18pF parallel
resonant crystals. The capacitor values, C1 and C2, shown in
Figure 2 below were determined using a 26.04167MHz, 18pF
XTAL_OUT
C1
33p
X1
18pF Parallel Crystal
XTAL_IN
C2
27p
Figure 2. CRYSTAL INPUt INTERFACE
843051AG
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8
REV. A DECEMBER 14, 2004
ICS843051
Integrated
Circuit
Systems, Inc.
FEMTOCLOCKS™ CRYSTAL-TO3.3V LVPECL CLOCK GENERATOR
LAYOUT GUIDELINE
parallel resonant crystal is used. The C1 = 27pF and C2 = 33pF
are recommended for frequency accuracy. The C1 and C2 values may be slightly adjusted for optimizing frequency accuracy.
Figure 3A shows a schematic example of the ICS843051. An
example of LVEPCL termination is shown in this schematic.
Additional LVPECL termination approaches are shown in the
LVPECL Termination Application Note. In this example, an 18 pF
VCCA
VCC
VCC
VCC
R2
10
C4
0.1u
C3
10uF
R3
133
R1
1K
R5
133
Zo = 50 Ohm
U1
Q
XTAL2
C2
33pF
19.44MHz
18pF
1
2
3
4
VCCA
VEE
XTAL_OUT
XTAL2
XTAL_IN
XTAL1
VCC
Q0
nQ0
FREQ_SEL
8
7
6
5
VCC
Zo = 50 Ohm
nQ
X1
XTAL1
+
-
ICS843051
R4
82.5
C5
0.1u
C1
27pF
R6
82.5
FIGURE 3A. ICS843051 SCHEMATIC EXAMPLE
PC BOARD LAYOUT EXAMPLE
Figure 3B shows an example of ICS843051 P.C. board layout.
The crystal X1 footprint shown in this example allows installation of either surface mount HC49S or through-hole HC49 package. The footprints of other components in this example are listed
in the Table 6. There should be at least one decoupling capacitor
per power pin. The decoupling capacitors should be located as
close as possible to the power pins. The layout assumes that
the board has clean analog power ground plane.
TABLE 6. FOOTPRINT TABLE
Reference
Size
C1, C2
0402
C3
0805
C4, C5
0603
R2
0603
NOTE: Table 6, lists component
sizes shown in this layout example.
FIGURE 3B. ICS843051 PC BOARD LAYOUT EXAMPLE
843051AG
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9
REV. A DECEMBER 14, 2004
ICS843051
Integrated
Circuit
Systems, Inc.
FEMTOCLOCKS™ CRYSTAL-TO3.3V LVPECL CLOCK GENERATOR
POWER CONSIDERATIONS
This section provides information on power dissipation and junction temperature for the ICS843051.
Equations and example calculations are also provided.
1. Power Dissipation.
The total power dissipation for the ICS843051 is the sum of the core power plus the power dissipated in the load(s).
The following is the power dissipation for VCC = 3.3V + 5% = 3.465V, which gives worst case results.
NOTE: Please refer to Section 3 for details on calculating power dissipated in the load.
•
•
Power (core)MAX = VCC_MAX * IEE_TYP = 3.465V * 85mA = 294.5mW
Power (outputs)MAX = 30mW/Loaded Output pair
Total Power_MAX (3.465V, with all outputs switching) = 294.5mW + 30mW = 324.5mW
2. Junction Temperature.
Junction temperature, Tj, is the temperature at the junction of the bond wire and bond pad and directly affects the reliability of the
device. The maximum recommended junction temperature for HiPerClockSTM devices is 125°C.
The equation for Tj is as follows: Tj = θJA * Pd_total + TA
Tj = Junction Temperature
θJA = Junction-to-Ambient Thermal Resistance
Pd_total = Total Device Power Dissipation (example calculation is in section 1 above)
TA = Ambient Temperature
In order to calculate junction temperature, the appropriate junction-to-ambient thermal resistance θJA must be used. Assuming a
moderate air flow of 1 meter per second and a multi-layer board, the appropriate value is 90.5°C/W per Table 7 below.
Therefore, Tj for an ambient temperature of 70°C with all outputs switching is:
70°C + 0.324W * 90.5°C/W = 99.3°C. This is well below the limit of 125°C.
This calculation is only an example. Tj will obviously vary depending on the number of loaded outputs, supply voltage, air flow,
and the type of board (single layer or multi-layer).
TABLE 7. THERMAL RESISTANCE θJA FOR 8-PIN TSSOP, FORCED CONVECTION
θJA by Velocity (Meters per Second)
Multi-Layer PCB, JEDEC Standard Test Boards
843051AG
0
1
2.5
101.7°C/W
90.5°C/W
89.8°C/W
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REV. A DECEMBER 14, 2004
ICS843051
Integrated
Circuit
Systems, Inc.
FEMTOCLOCKS™ CRYSTAL-TO3.3V LVPECL CLOCK GENERATOR
3. Calculations and Equations.
The purpose of this section is to derive the power dissipated into the load.
LVPECL output driver circuit and termination are shown in Figure 4.
VCC
Q1
VOUT
RL
50
VCC - 2V
FIGURE 4. LVPECL DRIVER CIRCUIT
AND
TERMINATION
To calculate worst case power dissipation into the load, use the following equations which assume a 50Ω load, and a termination
voltage of V - 2V.
CC
•
For logic high, VOUT = V
OH_MAX
(V
CCO_MAX
•
-V
OH_MAX
OL_MAX
CCO_MAX
-V
CC_MAX
– 0.9V
) = 0.9V
For logic low, VOUT = V
(V
=V
=V
CC_MAX
– 1.7V
) = 1.7V
OL_MAX
Pd_H is power dissipation when the output drives high.
Pd_L is the power dissipation when the output drives low.
Pd_H = [(V
OH_MAX
– (V
CC_MAX
- 2V))/R ] * (V
CC_MAX
L
-V
OH_MAX
) = [(2V - (V
CC_MAX
-V
OH_MAX
))/R ] * (V
CC_MAX
L
-V
OH_MAX
)=
[(2V - 0.9V)/50Ω] * 0.9V = 19.8mW
Pd_L = [(V
OL_MAX
– (V
CC_MAX
- 2V))/R ] * (V
L
CC_MAX
-V
OL_MAX
) = [(2V - (V
CC_MAX
-V
OL_MAX
))/R ] * (V
L
CC_MAX
-V
OL_MAX
)=
[(2V - 1.7V)/50Ω] * 1.7V = 10.2mW
Total Power Dissipation per output pair = Pd_H + Pd_L = 30mW
843051AG
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11
REV. A DECEMBER 14, 2004
ICS843051
Integrated
Circuit
Systems, Inc.
FEMTOCLOCKS™ CRYSTAL-TO3.3V LVPECL CLOCK GENERATOR
RELIABILITY INFORMATION
TABLE 8. θJAVS. AIR FLOW TABLE FOR 8 LEAD TSSOP
θJA by Velocity (Meters per Second)
Multi-Layer PCB, JEDEC Standard Test Boards
0
1
2.5
101.7°C/W
90.5°C/W
89.8°C/W
TRANSISTOR COUNT
The transistor count for ICS843051 is: 1892
843051AG
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12
REV. A DECEMBER 14, 2004
ICS843051
Integrated
Circuit
Systems, Inc.
PACKAGE OUTLINE - G SUFFIX
FOR
FEMTOCLOCKS™ CRYSTAL-TO3.3V LVPECL CLOCK GENERATOR
8 LEAD TSSOP
TABLE 9. PACKAGE DIMENSIONS
SYMBOL
Millimeters
Minimum
N
A
Maximum
8
--
1.20
A1
0.05
0.15
A2
0.80
1.05
b
0.19
0.30
c
0.09
0.20
D
2.90
3.10
E
E1
6.40 BASIC
4.30
e
4.50
0.65 BASIC
L
0.45
0.75
α
0°
8°
aaa
--
0.10
Reference Document: JEDEC Publication 95, MO-153
843051AG
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13
REV. A DECEMBER 14, 2004
ICS843051
Integrated
Circuit
Systems, Inc.
FEMTOCLOCKS™ CRYSTAL-TO3.3V LVPECL CLOCK GENERATOR
TABLE 10. ORDERING INFORMATION
Part/Order Number
Marking
Package
Count
Temperature
ICS843051AG
3051A
8 Lead TSSOP
100 per tube
0°C to 70°C
ICS843051AGT
3051A
8 Lead TSSOP on Tape and Reel
2500
0°C to 70°C
ICS843051AGLF
051AL
100 per tube
0°C to 70°C
ICS843051AGLFT
051AL
8 Lead "Lead-Free" TSSOP
8 Lead "Lead-Free" TSSOP
on Tape and Reel
2500
0°C to 70°C
The aforementioned trademarks, HiPerClockS™ and FemtoClocks™ are a trademark of Integrated Circuit Systems, Inc. or its subsidiaries in the United States and/or other countries.
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.
843051AG
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14
REV. A DECEMBER 14, 2004
ICS843051
Integrated
Circuit
Systems, Inc.
FEMTOCLOCKS™ CRYSTAL-TO3.3V LVPECL CLOCK GENERATOR
REVISION HISTORY SHEET
Rev
A
A
843051AG
Table
T10
Page
14
T10
1
14
Description of Change
Ordering Information Table - corrected count from 154 per tube to 100 per
tube.
Added Lead-Free bullet in Features section.
Ordering Information Table - added "Lead-Free" par t.
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15
Date
11/16/04
12/14/04
REV. A DECEMBER 14, 2004