ICS ICS844021I-01

PRELIMINARY
Integrated
Circuit
Systems, Inc.
ICS844021I-01
FEMTOCLOCKS™ CRYSTAL-TO- LVDS
CLOCK GENERATOR
GENERAL DESCRIPTION
FEATURES
The ICS844021I-01 is an Ethernet Clock
Generator and a member of the HiPerClocksTM
HiPerClockS™
family of high performance devices from ICS. The
ICS844021I-01 uses an 18pF parallel resonant
crystal over the range of 24.5MHz - 34MHz. For
Ether net applications, a 25MHz crystal is used. The
ICS844021I-01 has excellent <1ps phase jitter performance,
over the 1.875MHz - 20MHz integration range. The
ICS844021I-01 is packaged in a small 8-pin TSSOP, making
it ideal for use in systems with limited board space.
• (1) Differential LVDS output
ICS
• Crystal oscillator interface, 18pF parallel resonant crystal
(24.5MHz - 34MHz)
• Output frequency range: 122.5MHz - 170MHz
• VCO range: 490MHz - 680MHz
• RMS phase jitter @ 125MHz, using a 25MHz crystal
(1.875MHz - 20MHz): 0.45ps (typical)
• 3.3V or 2.5V operating supply
• -40°C to 85°C ambient operating temperature
COMMON CONFIGURATION TABLE - Gb ETHERNET
Inputs
Output Frequency
(MHz)
25
20
4
Multiplication
Value M/N
5
26.666
20
4
5
133.33
33.33
20
4
5
166.66
Crystal Frequency (MHz)
M
N
125
BLOCK DIAGRAM
PIN ASSIGNMENT
OE Pullup
XTAL_IN
OSC
XTAL_OUT
Phase
Detector
VCO
490MHz - 680MHz
N = ÷4 (fixed)
Q0
nQ0
VDDA
GND
XTAL_OUT
XTAL_IN
1
2
3
4
8
7
6
5
VDD
Q0
nQ0
OE
ICS844021I-01
8-Lead TSSOP
4.40mm x 3.0mm x 0.925mm
package body
G Package
Top View
M = ÷20 (fixed)
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.
844021AGI-01
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REV. A MARCH 29, 2005
1
PRELIMINARY
Integrated
Circuit
Systems, Inc.
ICS844021I-01
FEMTOCLOCKS™ CRYSTAL-TO- LVDS
CLOCK GENERATOR
TABLE 1. PIN DESCRIPTIONS
Number
Name
1
VDDA
Power
Analog supply pin.
2
GND
XTAL_OUT,
XTAL_IN
Power
5
OE
Input
6, 7
nQ0, Q0
Output
Power supply ground.
Crystal oscillator interface. XTAL_IN is the input,
XTAL_OUT is the output.
Output enable pin. When HIGH, Q0/nQ0 output is active.
When LOW, the Q0/nQ0 output is in a high impedance state.
LVCMOS/LVTTL interface levels.
Differential clock outputs. LVDS interface levels.
8
VDD
Power
Core supply pin.
3, 4
Type
Description
Input
Pullup
NOTE: Pullup refers to internal input resistors. See Table 2, Pin Characteristics, for typical values.
TABLE 2. PIN CHARACTERISTICS
Symbol
Parameter
CIN
Input Capacitance
4
pF
RPULLUP
Input Pullup Resistor
51
kΩ
844021AGI-01
Test Conditions
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2
Minimum
Typical
Maximum
Units
REV. A MARCH 29, 2005
PRELIMINARY
Integrated
Circuit
Systems, Inc.
ICS844021I-01
FEMTOCLOCKS™ CRYSTAL-TO- LVDS
CLOCK GENERATOR
ABSOLUTE MAXIMUM RATINGS
Supply Voltage, VDD
4.6V
NOTE: Stresses beyond those listed under Absolute
Inputs, VI
-0.5V to VDD + 0.5 V
Maximum Ratings may cause permanent damage to the
device. These ratings are stress specifications only. Functional
Outputs, IO (LVDS)
Continuous Current
Surge Current
10mA
15mA
Package Thermal Impedance, θJA
101.7°C/W (0 mps)
Storage Temperature, TSTG
-65°C to 150°C
operation of product at these conditions or any conditions beyond those listed in the DC Characteristics or AC Character-
istics 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%, TA = -40°C TO 85°C
Symbol
Parameter
Test Conditions
Minimum
Typical
Maximum
Units
VDD
Core Supply Voltage
3.135
3.3
3.465
V
VDDA
Analog Supply Voltage
3.135
3.3
3.465
V
IDD
Power Supply Current
TBD
mA
IDDA
Analog Supply Current
TBD
mA
TABLE 3B. POWER SUPPLY DC CHARACTERISTICS, VDD = VDDA = 2.5V±5%, TA = -40°C TO 85°C
Symbol
Parameter
Minimum
Typical
Maximum
Units
VDD
Core Supply Voltage
Test Conditions
2.375
2.5
2.625
V
VDDA
Analog Supply Voltage
2.375
2.5
2.625
V
IDD
Power Supply Current
TBD
mA
IDDA
Analog Supply Current
TBD
mA
TABLE 3C. LVCMOS/LVTTL DC CHARACTERISTICS, VDD = VDDA = 3.3V±5% OR 2.5V±5%, TA = -40°C TO 85°C
Symbol
Parameter
VIH
Input High Voltage
VIL
Input Low Voltage
IIH
Input High Current
OE
VDD = VIN = 3.465V or 2.625V
IIL
Input Low Current
OE
VDD = 3.465V or 2.625V, VIN = 0V
844021AGI-01
Test Conditions
Minimum
Typical
Maximum
Units
VDD = 3.3V
2
VDD + 0.3
V
VDD = 2.5V
1.7
VDD + 0.3
V
VDD = 3.3V
-0.3
0.8
V
VDD = 2.5V
-0.3
0.7
V
5
µA
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3
-150
µA
REV. A MARCH 29, 2005
PRELIMINARY
Integrated
Circuit
Systems, Inc.
ICS844021I-01
FEMTOCLOCKS™ CRYSTAL-TO- LVDS
CLOCK GENERATOR
TABLE 3D. LVDS DC CHARACTERISTICS, VDD = VDDA = 3.3V±5%, TA = -40°C TO 85°C
Symbol
Parameter
Test Conditions
Minimum
Typical
Maximum
Units
VOD
Differential Output Voltage
400
mV
Δ VOD
VOD Magnitude Change
40
mV
VOS
Offset Voltage
1.3
V
Δ VOS
VOS Magnitude Change
50
mV
NOTE: Please refer to Parameter Measurement Information for output information.
TABLE 3E. LVDS DC CHARACTERISTICS, VDD = VDDA = 2.5V±5%, TA = -40°C TO 85°C
Symbol
Parameter
VOD
Differential Output Voltage
Test Conditions
Minimum
Typical
400
Maximum
Units
mV
Δ VOD
VOD Magnitude Change
40
mV
VOS
Offset Voltage
1.2
V
Δ VOS
VOS Magnitude Change
50
mV
NOTE: Please refer to Parameter Measurement Information for output information.
TABLE 4. CRYSTAL CHARACTERISTICS
Parameter
Test Conditions
Minimum
Mode of Oscillation
Typical
Maximum
Units
Fundamental
34
MHz
Equivalent Series Resistance (ESR)
Frequency
24.5
50
Ω
Shunt Capacitance
7
pF
Drive Level
1
mW
Maximum
Units
170
MHz
TABLE 5A. AC CHARACTERISTICS, VDD = VDDA = 3.3V±5%, TA = -40°C TO 85°C
Symbol
Parameter
fOUT
Output Frequency
tjit(Ø)
tR / tF
RMS Phase Jitter ( Random);
NOTE 1
Output Rise/Fall Time
Test Conditions
Minimum
Typical
122.5
125MHz @ Integration Range:
1.875MHz - 20MHz
133.33MHz @ Integration Range:
1.875MHz - 20MHz
166.66MHz @ Integration Range:
1.875MHz - 20MHz
20% to 80%
odc
Output Duty Cycle
NOTE 1: Please refer to the Phase Noise Plots following this section.
0.45
ps
TBD
ps
TBD
ps
300
ps
50
%
TABLE 5B. AC CHARACTERISTICS, VDD = VDDA = 2.5V±5%, TA = -40°C TO 85°C
Symbol
Parameter
fOUT
Output Frequency
tjit(Ø)
tR / tF
RMS Phase Jitter ( Random);
NOTE 1
Output Rise/Fall Time
Test Conditions
Typical
122.5
125MHz @ Integration Range:
1.875MHz - 20MHz
133.33MHz @ Integration Range:
1.875MHz - 20MHz
166.66MHz @ Integration Range:
1.875MHz - 20MHz
20% to 80%
odc
Output Duty Cycle
NOTE 1: Please refer to the Phase Noise Plots following this section.
844021AGI-01
Minimum
www.icst.com/products/hiperclocks.html
4
Maximum
Units
170
MHz
0.45
ps
TBD
ps
TBD
ps
320
ps
50
%
REV. A MARCH 29, 2005
PRELIMINARY
Integrated
Circuit
Systems, Inc.
ICS844021I-01
FEMTOCLOCKS™ CRYSTAL-TO- LVDS
CLOCK GENERATOR
PARAMETER MEASUREMENT INFORMATION
SCOPE
Qx
3.3V±5%
POWER SUPPLY
Qx
2.5V±5%
POWER SUPPLY
LVDS
+ Float GND -
+ Float GND -
SCOPE
LVDS
nQx
nQx
LVDS 3.3V OUTPUT LOAD AC TEST CIRCUIT
LVDS 2.5V OUTPUT LOAD AC TEST CIRCUIT
Phase Noise Plot
Noise Power
nQ0
Q0
Pulse Width
t
Phase Noise Mask
odc =
f1
Offset Frequency
PERIOD
t PW
t PERIOD
f2
RMS Jitter = Area Under the Masked Phase Noise Plot
RMS PHASE JITTER
OUTPUT DUTY CYCLE/PULSE WIDTH/PERIOD
VVDD
DD
out
80%
DC Input
VSW I N G
Clock
Outputs
LVDS
➤
80%
20%
20%
tR
out
tF
➤
VOS/Δ VOS
➤
OFFSET VOLTAGE SETUP
OUTPUT RISE/FALL TIME
VDD
DD
LVDS
100
➤
VOD/Δ VOD
out
➤
DC Input
➤
out
DIFFERENTIAL OUTPUT VOLTAGE SETUP
844021AGI-01
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5
REV. A MARCH 29, 2005
PRELIMINARY
Integrated
Circuit
Systems, Inc.
ICS844021I-01
FEMTOCLOCKS™ CRYSTAL-TO- LVDS
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 ICS844021I-01 provides
separate power supplies to isolate any high switching
noise from the outputs to the internal PLL. VDD and VDDA 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 pin.
3.3V or 2.5V
VDD
.01μF
10Ω
V DDA
.01μF
10μF
FIGURE 1. POWER SUPPLY FILTERING
CRYSTAL INPUT INTERFACE
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 ICS844021I-01 has been characterized with 18pF parallel
resonant crystals. The capacitor values, C1 and C2, shown in
Figure 2 below were determined using a 25MHz, 18pF parallel
XTAL_OUT
C1
33p
X1
18pF Parallel Crystal
XTAL_IN
C2
27p
Figure 2. CRYSTAL INPUt INTERFACE
844021AGI-01
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REV. A MARCH 29, 2005
PRELIMINARY
Integrated
Circuit
Systems, Inc.
ICS844021I-01
FEMTOCLOCKS™ CRYSTAL-TO- LVDS
CLOCK GENERATOR
3.3V, 2.5V LVDS DRIVER TERMINATION
A general LVDS interface is shown in Figure 3. In a 100Ω
differential transmission line environment, LVDS drivers
require a matched load termination of 100Ω across near
the receiver input. For a multiple LVDS outputs buffer, if only
partial outputs are used, it is recommended to terminate the
un-used outputs.
3.3V or 2.5V
VDD
LVDS
+
R1
100
-
100 Ω Differential Transmission
FIGURE 3. TYPICAL LVDS DRIVER TERMINATION
844021AGI-01
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REV. A MARCH 29, 2005
PRELIMINARY
Integrated
Circuit
Systems, Inc.
ICS844021I-01
FEMTOCLOCKS™ CRYSTAL-TO- LVDS
CLOCK GENERATOR
RELIABILITY INFORMATION
TABLE 6. 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 ICS844021I-01 is: 2533
844021AGI-01
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REV. A MARCH 29, 2005
PRELIMINARY
Integrated
Circuit
Systems, Inc.
PACKAGE OUTLINE - G SUFFIX
FOR
ICS844021I-01
FEMTOCLOCKS™ CRYSTAL-TO- LVDS
CLOCK GENERATOR
8 LEAD TSSOP
TABLE 7. PACKAGE DIMENSIONS
SYMBOL
Millimeters
Minimum
N
Maximum
8
A
--
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
E
E1
3.10
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
844021AGI-01
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9
REV. A MARCH 29, 2005
PRELIMINARY
Integrated
Circuit
Systems, Inc.
ICS844021I-01
FEMTOCLOCKS™ CRYSTAL-TO- LVDS
CLOCK GENERATOR
TABLE 8. ORDERING INFORMATION
Part/Order Number
Marking
Package
Shipping Packaging
Temperature
ICS844021AGI-01
1AI01
8 lead TSSOP
tube
-40°C to 85°C
ICS844021AGI-01T
1AI01
8 lead TSSOP
2500 tape & reel
-40°C to 85°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 and industrial applications. Any other applications such as those requiring 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.
844021AGI-01
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10
REV. A MARCH 29, 2005