ICS ICS840002AG

ICS840002-01
Integrated
Circuit
Systems, Inc.
FEMTOCLOCKS™ CRYSTAL-TOLVCMOS/LVTTL FREQUENCY SYNTHESIZER
GENERAL DESCRIPTION
FEATURES
The ICS840002-01 is a 2 output LVCMOS/LVTTL
Synthesizer optimized to generate Ethernet
HiPerClockS™ reference clock frequencies and is a member of
the HiPerClocksTM family of high performance
clock solutions from ICS. Using a 25MHz 18pF
parallel resonant crystal, the following frequencies can be
generated based on the 2 frequency select pins (F_SEL1:0):
156.25MHz, 125MHz, and 62.5MHz. The ICS840002-01 uses
ICS’ 3rd generation low phase noise VCO technology and can
achieve 1ps or lower typical random rms phase jitter, easily
meeting Ethernet jitter requirements. The ICS840002-01 is
packaged in a small 16-pin TSSOP package.
• Two LVCMOS/LVTTL outputs @ 3.3V,
17Ω typical output impedance
ICS
• Selectable crystal oscillator interface
or LVCMOS/LVTTL single-ended input
• Output frequency range: 56MHz - 175MHz
• VCO range: 560MHz - 700MHz
• Output skew: 12ps (maximum)
• RMS phase jitter at 156.25MHZ (1.875MHz - 20MHz):
0.47ps (typical)
Phase noise:
Offset
Noise Power
100Hz ............... -97.4 dBc/Hz
1kHz .............. -120.2 dBc/Hz
10kHz .............. -127.6 dBc/Hz
100kHz .............. -126.1 dBc/Hz
• Full 3.3V or 3.3V core/2.5V output supply mode
• -30°C to 85°C ambient operating temperature
• Available in both standard and lead-free RoHS compliant
packages
FREQUENCY SELECT FUNCTION TABLE
Inputs
F_SEL1 F_SEL0
M Divider Value
N Divider Value
Output Frequency
(25MHz Ref.)
0
0
25
4
156.25
0
1
25
5
125
1
0
25
10
62.5
1
1
25
5
125
BLOCK DIAGRAM
OE
PIN ASSIGNMENT
Pullup
F_SEL0
nXTAL_SEL
TEST_CLK
OE
MR
nPLL_SEL
VDDA
VDD
2
F_SEL1:0 Pullup:Pullup
nPLL_SEL Pulldown
nXTAL_SEL
XTAL_IN
Pulldown
25MHz
OSC
F_SEL1:0
0
1
00
01
10
11
XTAL_OUT
TEST_CLK Pulldown
1
Phase
Detector
VCO
0
N
÷4
÷5
÷10
÷5
M = ÷25 (fixed)
MR
840002AG-01
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
F_SEL1
GND
GND
Q0
Q1
VDDO
XTAL_IN
XTAL_OUT
Q0
ICS840002-01
Q1
16-Lead TSSOP
4.4mm x 5.0mm x 0.92mm
package body
G Package
Top View
Pulldown
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1
REV. B JANUARY 13, 2006
ICS840002-01
Integrated
Circuit
Systems, Inc.
FEMTOCLOCKS™ CRYSTAL-TOLVCMOS/LVTTL FREQUENCY SYNTHESIZER
TABLE 1. PIN DESCRIPTIONS
Number
Name
1
F_SEL0
Input
Type
Pullup
Description
2
nXTAL_SEL
Input
Pulldown
3
TEST_CLK
Input
Pulldown
4
OE
Input
Pullup
5
MR
Input
Pulldown
6
nPLL_SEL
Input
Pulldown
7
VDDA
Power
8
9,
10
11
VDD
XTAL_OUT,
XTAL_IN
VDDO
Power
Power
Core supply pin.
Cr ystal oscillator interface. XTAL_OUT is the output.
XTAL_IN is the input.
Output supply pin.
12, 13
Q1, Q0
Output
Single-ended clock outputs. LVCMOS/LVTTL interface levels.
14, 15
GND
Power
Power supply ground.
16
F_SEL1
Input
Input
Pullup
Frequency select pin. LVCMOS/LVTTL interface levels.
Selects between the cr ystal or TEST_CLK inputs as the PLL reference
source. When HIGH, selects TEST_CLK. When LOW, selects XTAL
inputs. LVCMOS/LVTTL interface levels.
Single-ended LVCMOS/LVTTL clock input.
Output enable pin. When HIGH, the outputs are active. When LOW, the
outputs are in a high impedance state. LVCMOS/LVTTL interface levels.
Active HIGH Master Reset. When logic HIGH, the internal dividers are
reset causing active outputs to go low. When logic LOW, the internal
dividers and the outputs are enabled. LVCMOS/LVTTL interface levels.
PLL Bypass. When LOW, the output is driven from the VCO output.
When HIGH, the PLL is bypassed and the output frequency =
reference clock frequency/N output divider.
LVCMOS/LVTTL interface levels.
Analog supply pin.
Frequency select pin. LVCMOS/LVTTL interface levels.
NOTE: Pullup and Pulldown refer to internal input resistors. See Table 2, Pin Characteristics, for typical values.
TABLE 2. PIN CHARACTERISTICS
Symbol
Parameter
CIN
Input Capacitance
Test Conditions
Minimum
Typical
Maximum
4
Units
pF
CPD
Power Dissipation Capacitance
8
pF
RPULLUP
Input Pullup Resistor
51
kΩ
RPULLDOWN
Input Pulldown Resistor
51
kΩ
ROUT
Output Impedance
840002AG-01
3.3V±5%
14
17
21
Ω
2.5V±5%
16
21
25
Ω
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2
REV. B JANUARY 13, 2006
ICS840002-01
Integrated
Circuit
Systems, Inc.
FEMTOCLOCKS™ CRYSTAL-TOLVCMOS/LVTTL FREQUENCY SYNTHESIZER
ABSOLUTE MAXIMUM RATINGS
Supply Voltage, VDD
4.6V
Inputs, VI
-0.5V to VDD + 0.5 V
Outputs, VO
-0.5V to VDDO + 0.5V
Package Thermal Impedance, θJA
89°C/W (0 lfpm)
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, VDD = VDDA = 3.3V±5%, VDDO = 3.3V±5% OR 2.5V±5%, TA = 0°C TO 70°C
Symbol
VDD
Parameter
Core Supply Voltage
VDDA
Analog Supply Voltage
Test Conditions
Minimum
3.135
Typical
3.3
Maximum
3.465
Units
V
3.135
3.3
3.465
V
3.135
3.3
3.465
V
2.375
2.5
VDDO
Output Supply Voltage
2.625
V
IDD
Power Supply Current
100
mA
IDDA
IDDO
Analog Supply Current
Output Supply Current
12
5
mA
mA
TABLE 3B. LVCMOS/LVTTL DC CHARACTERISTICS, VDD = VDDA = 3.3V±5%, VDDO = 3.3V±5% OR 2.5V±5%, TA = -30°C TO 85°C
Symbol Parameter
Test Conditions
VIH
Input High Voltage
VIL
Input Low Voltage
IIH
Input
High Current
OE, F_SEL0, F_SEL1
nPLL_SEL, MR,
nXTAL_SEL, TEST_CLK
OE, F_SEL0, F_SEL1
IIL
Input
Low Current
nPLL_SEL, MR,
nXTAL_SEL, TEST_CLK
VOH
Output High Voltage; NOTE 1
VOL
Output Low Voltage; NOTE 1
VDD = VIN = 3.465V
or 2.625V
VDD = VIN = 3.465V
or 2.625V
VDD = 3.465V or 2.625V,
VIN = 0V
Minimum Typical
Maximum
Units
2
VDD + 0.3
V
-0.3
0.8
V
5
µA
150
µA
-150
µA
-5
µA
VDDO = 3.465V±5%
2.6
V
VDDO = 2.5V±5%
1.8
V
VDD = 3.465V or 2.625V,
VIN = 0V
VDDO = 3.3V or 2.5V±5%
0.5
V
NOTE 1: Outputs terminated with 50Ω to VDDO/2. See Parameter Measurement Information, Output Load Test Circuits.
840002AG-01
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3
REV. B JANUARY 13, 2006
ICS840002-01
Integrated
Circuit
Systems, Inc.
FEMTOCLOCKS™ CRYSTAL-TOLVCMOS/LVTTL FREQUENCY SYNTHESIZER
TABLE 4. CRYSTAL CHARACTERISTICS
Parameter
Test Conditions
Minimum
Mode of Oscillation
Typical
Maximum
Units
Fundamental
Frequency
25
MHz
Equivalent Series Resistance (ESR)
50
Ω
Shunt Capacitance
7
pF
Drive Level
1
mW
Maximum
Units
NOTE: Characterized using an 18pF parallel resonant cr ystal.
TABLE 5A. AC CHARACTERISTICS, VDD = VDDA = VDDO = 3.3V±5%, TA = -30°C TO 85°C
Symbol
Parameter
fOUT
Output Frequency
t sk(o)
Output Skew; NOTE 1, 3
t jit(Ø)
RMS Phase Jitter (Random);
NOTE 2
tR / tF
Output Rise/Fall Time
Test Conditions
Minimum
Typical
F_SEL[1:0] = 00
140
175
MHz
F_SEL[1:0] = 01
112
140
MHz
F_SEL[1:0] = 10 or 11
56
70
MHz
12
ps
156.25MHz (1.875MHz - 20MHz)
0.47
ps
125MHz (1.875MHz - 20MHz)
0.57
ps
62.5MHz (1.875MHz - 20MHz)
0.51
20% to 80%
200
odc
Output Duty Cycle
46
NOTE 1: Defined as skew between outputs at the same supply voltages and with equal load conditions.
Measured at VDDO/2.
NOTE 2: Please refer to the Phase Noise Plot.
NOTE 3: This parameter is defined in accordance with JEDEC Standard 65.
ps
700
ps
54
%
TABLE 5B. AC CHARACTERISTICS, VDD = VDDA = 3.3V±5%, VDDO = 2.5V±5%, TA = -30°C TO 85°C
Symbol
fOUT
Parameter
Output Frequency
t sk(o)
Output Skew; NOTE 1, 3
t jit(Ø)
RMS Phase Jitter (Random);
NOTE 2
Test Conditions
Minimum
Maximum
Units
F_SEL[1:0] = 00
140
175
MHz
F_SEL[1:0] = 01
112
140
MHz
F_SEL[1:0] = 10 or 11
56
68
MHz
12
ps
156.25MHz (1.875MHz - 20MHz)
tR / tF
Output Rise/Fall Time
Typical
0.47
125MHz (1.875MHz - 20MHz)
0.55
ps
62.5MHz (1.875MHz - 20MHz)
0.49
ps
20% to 80%
200
odc
Output Duty Cycle
46
NOTE 1: Defined as skew between outputs at the same supply voltages and with equal load conditions.
Measured at VDDO/2.
NOTE 2: Please refer to the Phase Noise Plot.
NOTE 3: This parameter is defined in accordance with JEDEC Standard 65.
840002AG-01
ps
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4
700
ps
54
%
REV. B JANUARY 13, 2006
ICS840002-01
Integrated
Circuit
Systems, Inc.
FEMTOCLOCKS™ CRYSTAL-TOLVCMOS/LVTTL FREQUENCY SYNTHESIZER
TYPICAL PHASE NOISE AT 62.5MHZ @3.3V
➤
0
-10
-20
1Gb Ethernet Filter
-40
62.5MHz
-50
RMS Phase Jitter (Random)
1.875MHz to 20MHz = 0.51ps (typical)
-60
-70
-80
-90
Raw Phase Noise Data
-100
➤
NOISE POWER dBc
Hz
-30
-110
-120
-130
-140
-150
➤
-160
-170
-180
Phase Noise Result by adding
1Gb Ethernet Filter to raw data
-190
100
1k
10k
100k
1M
10M
100M
OFFSET FREQUENCY (HZ)
TYPICAL PHASE NOISE AT 156.25MHZ @3.3V
0
➤
-10
-20
10Gb Ethernet Filter
-40
156.25MHz
-50
RMS Phase Jitter (Random)
1.875MHz to 20MHz = 0.47ps (typical)
-60
-70
-80
-90
Raw Phase Noise Data
-100
-110
➤
NOISE POWER dBc
Hz
-30
-120
-130
-140
-150
➤
-160
-170
Phase Noise Result by adding
10Gb Ethernet Filter to raw data
-180
-190
100
1k
10k
100k
1M
10M
100M
OFFSET FREQUENCY (HZ)
840002AG-01
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5
REV. B JANUARY 13, 2006
ICS840002-01
Integrated
Circuit
Systems, Inc.
FEMTOCLOCKS™ CRYSTAL-TOLVCMOS/LVTTL FREQUENCY SYNTHESIZER
PARAMETER MEASUREMENT INFORMATION
1.65V±5%
2.05V±5% 1.25V±5%
SCOPE
VDD,
VDDA, VDDO
VDD,
VDDA
Qx
LVCMOS
SCOPE
VDDO
Qx
LVCMOS
GND
GND
-1.65V±5%
-1.25V±5%
3.3V CORE/3.3V OUTPUT LOAD AC TEST CIRCUIT
3.3V CORE/2.5V OUTPUT LOAD AC TEST CIRCUIT
Phase Noise Plot
Noise Power
V
DDO
Qx
2
Phase Noise Mask
V
DDO
Qy
Offset Frequency
f1
2
tsk(o)
f2
RMS Jitter = Area Under the Masked Phase Noise Plot
RMS PHASE JITTER
OUTPUT SKEW
V
80%
DDO
80%
2
Q0, Q1
Clock
Outputs
t PW
20%
20%
tR
t
tF
odc =
PERIOD
t PW
x 100%
t PERIOD
OUTPUT RISE/FALL TIME
840002AG-01
OUTPUT DUTY CYCLE/PULSE WIDTH/PERIOD
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6
REV. B JANUARY 13, 2006
ICS840002-01
Integrated
Circuit
Systems, Inc.
FEMTOCLOCKS™ CRYSTAL-TOLVCMOS/LVTTL FREQUENCY SYNTHESIZER
APPLICATION INFORMATION
POWER SUPPLY FILTERING TECHNIQUES
As in any high speed analog circuitry, the power supply pins
are vulnerable to random noise. The ICS840002-01 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. The 10Ω resistor can also be replaced by a ferrite bead.
3.3V
VDD
.01μF
10Ω
VDDA
.01μF
10μF
FIGURE 1. POWER SUPPLY FILTERING
CRYSTAL INPUT INTERFACE
The ICS840002-01 has been characterized with 18pF parallel resonant crystals. The capacitor values shown in Figure 2
below were determined using a 25MHz 18pF parallel resonant crystal and were chosen to minimize the ppm error.
XTAL_IN
C1
22p
X1
18pF Parallel Cry stal
XTAL_OUT
C2
22p
ICS84332
ICS840002-01
Figure 2. CRYSTAL INPUt INTERFACE
840002AG-01
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7
REV. B JANUARY 13, 2006
ICS840002-01
Integrated
Circuit
Systems, Inc.
FEMTOCLOCKS™ CRYSTAL-TOLVCMOS/LVTTL FREQUENCY SYNTHESIZER
RECOMMENDATIONS FOR UNUSED INPUT AND OUTPUT PINS
INPUTS:
OUTPUTS:
CRYSTAL INPUT:
For applications not requiring the use of the crystal oscillator
input, both XTAL_IN and XTAL_OUT can be left floating.
Though not required, but for additional protection, a 1kΩ
resistor can be tied from XTAL_IN to ground.
LVCMOS OUTPUT:
All unused LVCMOS output can be left floating. We
recommend that there is no trace attached.
TEST_CLK INPUT:
For applications not requiring the use of the test clock, it can
be left floating. Though not required, but for additional
protection, a 1kΩ resistor can be tied from the TEST_CLK to
ground.
LVCMOS CONTROL PINS:
All control pins have internal pull-ups or pull-downs; additional
resistance is not required but can be added for additional
protection. A 1kΩ resistor can be used.
LAYOUT GUIDELINE
C2=22pF are recommended for frequency accuracy. For different board layout, the C1 and C2 may be slightly adjusted for
optimizing frequency accuracy. 1KΩ pullup or pulldown resistors can be used for the logic control input pins.
Figure 3 shows a schematic example of the ICS840002-01. An
example of LVCMOS termination is shown in this schematic.
Additional LVCMOS termination approaches are shown in the
LVCMOS Termination Application Note. In this example, an 18
pF parallel resonant 25MHz crystal is used. The C1=22pF and
Logic Control Input Examples
Set Logic
Input to
'1'
VDD
RU1
1K
Set Logic
Input to
'0'
VDD
R2
33
RU2
Not Install
To Logic
Input
pins
RD1
Not Install
To Logic
Input
pins
U1
RD2
1K
VDD
1
2
3
4
5
6
7
8
VDDA
R1
10
C3
10uF
Zo = 50 Ohm
VDD
C4
0.01u
LVCMOS
FSEL0
XTAL_SEL
TEST_CLK
OE
MR
nPLL_SEL
VDDA
VDD
16
15
14
13
12
11
10
9
FSEL1
GND
GND
Q0
Q1
VDDO
XTAL_IN
XTAL_OUT
VDD
R3
100
C6
0.1u
Zo = 50 Ohm
C5
0.1u
ICS840002-01
R4
100
XTAL2
If not using the crystal input, it can be left floating.
For additional protection the XTAL_IN pin can be
tied to ground.
LVCMOS
C2
22pF
X1
XTAL1
Optional Termination
C1
22pF
Unused output can be left floating. There should
no trace attached to unused output. Device
characterized with all outputs terminated.
FIGURE 3. ICS840002-01 SCHEMATIC EXAMPLE
840002AG-01
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8
REV. B JANUARY 13, 2006
ICS840002-01
Integrated
Circuit
Systems, Inc.
FEMTOCLOCKS™ CRYSTAL-TOLVCMOS/LVTTL FREQUENCY SYNTHESIZER
RELIABILITY INFORMATION
TABLE 6.
θJAVS. AIR FLOW TABLE FOR 16 LEAD TSSOP
θJA by Velocity (Linear Feet per Minute)
Single-Layer PCB, JEDEC Standard Test Boards
Multi-Layer PCB, JEDEC Standard Test Boards
0
200
500
137.1°C/W
89.0°C/W
118.2°C/W
81.8°C/W
106.8°C/W
78.1°C/W
NOTE: Most modern PCB designs use multi-layered boards. The data in the second row pertains to most designs.
TRANSISTOR COUNT
The transistor count for ICS840002-01 is: 3085
840002AG-01
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9
REV. B JANUARY 13, 2006
ICS840002-01
Integrated
Circuit
Systems, Inc.
PACKAGE OUTLINE - G SUFFIX
FOR
FEMTOCLOCKS™ CRYSTAL-TOLVCMOS/LVTTL FREQUENCY SYNTHESIZER
16 LEAD TSSOP
TABLE 7. PACKAGE DIMENSIONS
Millimeters
SYMBOL
Minimum
N
A
Maximum
16
--
1.20
A1
0.05
0.15
A2
0.80
1.05
b
0.19
0.30
c
0.09
0.20
D
4.90
5.10
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
840002AG-01
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10
REV. B JANUARY 13, 2006
Integrated
Circuit
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ICS840002-01
FEMTOCLOCKS™ CRYSTAL-TOLVCMOS/LVTTL FREQUENCY SYNTHESIZER
TABLE 8. ORDERING INFORMATION
Part/Order Number
Marking
Package
Shipping Packaging Temperature
ICS840002AG-01
40002A01
16 Lead TSSOP
tube
-30°C to 85°C
ICS840002AG-01T
40002A01
16 Lead TSSOP
2500 tape & reel
-30°C to 85°C
ICS840002AG-01LF
0002A01L
16 Lead "Lead-Free" TSSOP
tube
-30°C to 85°C
ICS840002AG-01LFT
0002A01L
16 Lead "Lead-Free" TSSOP
2500 tape & reel
-30°C to 85°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 aforementioned trademarks, HiPerClockS and FEMTOCLOCKS are trademarks 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.
840002AG-01
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11
REV. B JANUARY 13, 2006
Integrated
Circuit
Systems, Inc.
ICS840002-01
FEMTOCLOCKS™ CRYSTAL-TOLVCMOS/LVTTL FREQUENCY SYNTHESIZER
REVISION HISTORY SHEET
Rev
B
Table
Page
1
T4
4
8
11
T8
840002AG-01
Description of Change
Features Section - corrected the integration range from 1.875MHz - 175MHz
to 1.875MHz - 20MHz in the RMS phase jitter bullet.
Cr ystal Characteristics Table - added Drive Level.
Added Recommendations for Unused Input and Output Pins.
Ordering Information Table - corrected standard marking and
added Lead-Free par t number, marking and note.
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12
Date
1/13/06
REV. B JANUARY 13, 2006