ICS ICS844246AMLFT

PRELIMINARY
Integrated
Circuit
Systems, Inc.
ICS844246
FEMTOCLOCKS™CRYSTAL-TO-LVDS
FREQUENCY SYNTHESIZER W/INTEGRATED FANOUT BUFFER
GENERAL DESCRIPTION
FEATURES
The ICS844246 is a Crystal-to-LVDS Clock
Synthesizer/Fanout Buffer designed for Fibre
HiPerClockS™
Channel and Gigabit Ethernet applications and
is a member of the HiperClockS™ family of
High Performance Clock Solutions from ICS.
The output frequency can be set using the frequency
select pins and a 25MHz crystal for Ethernet frequencies, or a 26.5625MHz crystal for a Fibre Channel.
The low phase noise characteristics of the ICS844246
make it an ideal clock for these demanding applications.
• Six LVDS outputs
ICS
• Crystal oscillator interface
• Output frequency range: 53.125MHz to 333.3333MHz
• Crystal input frequency range: 25MHz to 33.333MHz
• RMS phase jitter at 125MHz, using a 25MHz crystal
(1.875MHz to 20MHz): 0.39ps (typical)
• Full 3.3V or 3.3V core, 2.5V output supply mode
• 0°C to 70°C ambient operating temperature
• Industrial temperature information available upon request
• Available in both standard and lead-free RoHS-compliant
packages
SELECT FUNCTION TABLE
Inputs
Function
FB_SEL
N_SEL1
N_SEL0
M Divide
N Divide
M/N
0
0
0
20
2
10
0
0
1
20
4
5
0
1
0
20
5
4
0
1
1
20
8
2.5
1
0
0
24
3
8
1
0
1
24
4
6
1
1
0
24
6
4
1
1
1
24
12
2
BLOCK DIAGRAM
PIN ASSIGNMENT
Q0
nQ0
PLL_BYPASS
Pullup
Q1
1
XTAL_IN
OSC
PLL
0
nQ1
Output
Divider
XTAL_OUT
nQ2
Q3
Feedback
Divider
FB_SEL
N_SEL1
N_SEL0
Q2
nQ3
Pulldown
Q4
Pullup
nQ4
Pullup
Q5
nQ5
VDDO
VDDO
nQ2
Q2
nQ1
Q1
nQ0
Q0
PLL_BYPASS
V DDA
VDD
FB_SEL
1
2
3
4
5
6
7
8
9
10
11
12
24
23
22
21
20
19
18
17
16
15
14
13
Q3
nQ3
Q4
nQ4
Q5
nQ5
N_SEL1
GND
GND
N_SEL0
XTAL_OUT
XTAL_IN
ICS843246
24-Lead, 300-MIL SOIC
7.5mm x 15.33mm x 2.3mm
body package
M Package
Top View
24-Lead TSSOP
4.40mm x 7.8mm x 0.92mm
body package
G Package
Top View
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.
844246AM
www.icst.com/products/hiperclocks.html
1
REV. A SEPTEMBER 29, 2005
PRELIMINARY
Integrated
Circuit
Systems, Inc.
ICS844246
FEMTOCLOCKS™CRYSTAL-TO-LVDS
FREQUENCY SYNTHESIZER W/INTEGRATED FANOUT BUFFER
TABLE 1. PIN DESCRIPTIONS
Number
Name
1, 2
VDDO
3, 4
5, 6
Type
Description
Power
Output supply pins.
nQ2, Q2
Output
Differential output pair. LVDS interface levels.
nQ1, Q1
Output
Differential output pair. LVDS interface levels.
7, 8
nQ0, Q0
Output
9
PLL_BYPASS
Input
10
VDDA
Power
Differential output pair. LVDS interface levels.
Selects between the PLL and cr ystal inputs as the input to the dividers.
When LOW, selects PLL. When HIGH, selects XTAL_IN, XTAL_OUT.
LVCMOS / LVTTL interface levels.
Analog supply pin.
11
VDD
Power
Core supply pin.
12
13,
14
15,
18
16, 17
FB_SEL
XTAL_IN,
XTAL_OUT
N_SEL0
N_SEL1
GND
Input
19, 20
nQ5, Q5
Output
Differential output pair. LVDS interface levels.
21, 22
nQ4, Q4
Output
Differential output pair. LVDS interface levels.
23, 24
nQ3, Q3
Output
Differential output pair. LVDS interface levels.
Input
Input
Pullup
Pulldown Feedback frequency select pin. LVCMOS/LVTTL interface levels.
Cr ystal oscillator interface. XTAL_IN is the input.
XTAL_OUT is the output.
Pullup
Output frequency select pin. LVCMOS/LVTTL interface levels.
Power supply ground.
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
4
pF
RPULLUP
Input Pullup Resistor
51
kΩ
RPULLDOWN
Input Pulldown Resistor
51
kΩ
844246AM
Test Conditions
www.icst.com/products/hiperclocks.html
2
Minimum
Typical
Maximum
Units
REV. A SEPTEMBER 29, 2005
PRELIMINARY
Integrated
Circuit
Systems, Inc.
ICS844246
FEMTOCLOCKS™CRYSTAL-TO-LVDS
FREQUENCY SYNTHESIZER W/INTEGRATED FANOUT BUFFER
CRYSTAL FUNCTION TABLE
Inputs
XTAL (MHz)
FB_SEL
Function
N_SEL1
N_SEL0
M
VCO (MHz)
N
Output (MHz)
25
0
0
0
20
500
2
250
25
0
0
1
20
500
4
125
25
0
1
0
20
500
5
10 0
25
0
1
1
20
500
8
62.5
25
1
0
0
24
600
3
200
25
1
0
1
24
600
4
150
25
1
1
0
24
600
6
100
25
1
1
1
24
600
12
50
26.5625
0
1
0
20
531.25
5
106.25
26.5625
1
0
0
24
637.5
3
212.5
26.5625
1
0
1
24
637.5
4
159.375
26.5625
1
1
0
24
637.5
6
106.25
26.5625
1
1
1
24
637.5
12
53.125
30
0
0
0
20
600
2
300
30
0
0
1
20
600
4
150
30
0
1
0
20
600
5
12 0
30
0
1
1
20
600
8
75
31.25
0
0
0
20
625
2
312.5
31.25
0
0
1
20
62 5
4
156.25
31.25
0
1
0
20
62 5
5
12 5
31.25
0
1
1
20
625
8
78.125
33.3333
0
0
0
20
666.6667
2
333.3333
33.3333
0
0
1
20
666.6667
4
166.6667
33.3333
0
1
0
20
666.6667
5
133.3333
33.3333
0
1
1
20
666.6667
8
83.3333
844246AM
www.icst.com/products/hiperclocks.html
3
REV. A SEPTEMBER 29, 2005
PRELIMINARY
Integrated
Circuit
Systems, Inc.
ICS844246
FEMTOCLOCKS™CRYSTAL-TO-LVDS
FREQUENCY SYNTHESIZER W/INTEGRATED FANOUT BUFFER
ABSOLUTE MAXIMUM RATINGS
Supply Voltage, VDD
4.6V
Inputs, VI
-0.5V to VDD + 0.5V
Outputs, IO
Continuous Current
Surge Current
10mA
15mA
Package Thermal Impedance, θJA
24 Lead SOIC
24 Lead TSSOP
50°C/W (0 lfpm)
70°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 4A. POWER SUPPLY DC CHARACTERISTICS, VDD = VDDA = VDDO = 3.3V±5%, TA = 0°C TO 70°C
Symbol
Parameter
Minimum
Typical
Maximum
Units
VDD
Core Supply Voltage
Test Conditions
3.135
3. 3
3.465
V
VDDA
Analog Supply Voltage
3.135
3. 3
3.465
V
VDDO
Output Supply Voltage
3.135
3.3
3.465
IDD
Power Supply Current
125
V
mA
IDDA
Analog Supply Current
7
mA
IDDO
Output Supply Current
127
mA
TABLE 4B. POWER SUPPLY DC CHARACTERISTICS, VDD = VDDA = 3.3V±5%, VDDO = 2.5V±5%, TA = 0°C TO 70°C
Symbol
Parameter
Test Conditions
Minimum
Typical
Maximum
VDD
Core Supply Voltage
3.135
3. 3
3.465
V
VDDA
Analog Supply Voltage
3.135
3. 3
3.465
V
VDDO
Output Supply Voltage
2.375
2. 5
2.625
IDD
Power Supply Current
125
Units
V
mA
IDDA
Analog Supply Current
7
mA
IDDO
Output Supply Current
115
mA
TABLE 4C. LVCMOS / LVTTL DC CHARACTERISTICS, VDD = VDDA = 3.3V±5%, VDDO = 3.3V±5% OR 2.5V±5%, TA = 0°C TO 70°C
Symbol
Parameter
VIH
Input High Voltage
VIL
Input Low Voltage
IIH
Input High Current
IIL
Input Low Current
844246AM
Test Conditions
Minimum
2
-0.3
FB_SEL
PLL_BYPASS,
N_SEL0, N_SEL1
FB_SEL
PLL_BYPASS,
N_SEL0, N_SEL1
Typical
Maximum
Units
VDD + 0.3
V
0. 8
V
VDD = VIN = 3.465V
150
µA
VDD = VIN = 3.465V
5
µA
VDD = 3.465V, VIN = 0V
-5
µA
VDD = 3.465V, VIN = 0V
-150
µA
www.icst.com/products/hiperclocks.html
4
REV. A SEPTEMBER 29, 2005
PRELIMINARY
Integrated
Circuit
Systems, Inc.
ICS844246
FEMTOCLOCKS™CRYSTAL-TO-LVDS
FREQUENCY SYNTHESIZER W/INTEGRATED FANOUT BUFFER
TABLE 4D. LVDS DC CHARACTERISTICS, VDD = VDDA = VDDO = 3.3V±5% TA = 0°C TO 70°C
Symbol
Parameter
VOD
Differential Output Voltage
Δ VOD
VOD Magnitude Change
VOS
Offset Voltage
Δ VOS
VOS Magnitude Change
Test Conditions
Minimum
Typical
Maximum
Units
387
mV
40
mV
1.29
V
50
mV
NOTE: Please refer to Parameter Measurement Information for output information.
TABLE 4E. LVDS DC CHARACTERISTICS, VDD = VDDA = 3.3V±5%, VDDO = 2.5V±5%, TA = 0°C TO 70°C
Symbol
Parameter
VOD
Differential Output Voltage
Test Conditions
Minimum
Typical
379
Maximum
Units
mV
Δ VOD
VOD Magnitude Change
40
mV
VOS
Offset Voltage
Δ VOS
VOS Magnitude Change
1.24
V
50
mV
TABLE 5. CRYSTAL CHARACTERISTICS
Parameter
Test Conditions
Minimum
Mode of Oscillation
Typical Maximum
Units
Fundamental
Frequency
25
33.333
MHz
Equivalent Series Resistance (ESR)
50
Ω
Shunt Capacitance
7
pF
Drive Level
1
mW
NOTE: Characterized using an 18pf parallel resonant crystal.
844246AM
www.icst.com/products/hiperclocks.html
5
REV. A SEPTEMBER 29, 2005
PRELIMINARY
Integrated
Circuit
Systems, Inc.
ICS844246
FEMTOCLOCKS™CRYSTAL-TO-LVDS
FREQUENCY SYNTHESIZER W/INTEGRATED FANOUT BUFFER
TABLE 6A. AC CHARACTERISTICS, VDD = VDDA = VDDO = 3.3V±5%, TA = 0°C TO 70°C
Symbol Parameter
FOUT
Output Frequency
t jit(Ø)
RMS Phase Jitter (Random)
t sk(o)
Output Skew; NOTE 1, 2
tR / tF
Output Rise/Fall Time
odc
Output Duty Cycle
Test Conditions
Minimum
Typical
53.125
125MHz, Integration Range:
1.875MHz - 20MHz
Maximum
Units
333.33
MHz
0.39
20% to 80%
ps
TBD
ps
355
ps
50
PLL Lock Time
tLOCK
See Parameter Measurement Information section.
NOTE 1: Defined as skew between outputs at the same supply voltage and with equal load conditions.
Measured at the output differential crossing points.
NOTE 2: This parameter is defined in accordance with JEDEC Standard 65.
%
1
ms
Maximum
Units
333.33
MHz
TABLE 6B. AC CHARACTERISTICS, VDD = VDDA = 3.3V±5%, VDDO = 2.5V±5%, TA = 0°C TO 70°C
Symbol Parameter
FOUT
Test Conditions
Minimum
Output Frequency
t jit(Ø)
RMS Phase Jitter (Random)
t sk(o)
Output Skew; NOTE 1, 2
tR / tF
Output Rise/Fall Time
odc
Output Duty Cycle
Typical
53.125
125MHz, Integration Range:
1.875MHz - 20MHz
20% to 80%
0.38
ps
TBD
ps
380
ps
50
PLL Lock Time
tLOCK
See Parameter Measurement Information section.
NOTE 1: Defined as skew between outputs at the same supply voltage and with equal load conditions.
Measured at the output differential crossing points.
NOTE 2: This parameter is defined in accordance with JEDEC Standard 65.
844246AM
www.icst.com/products/hiperclocks.html
6
%
1
ms
REV. A SEPTEMBER 29, 2005
PRELIMINARY
Integrated
Circuit
Systems, Inc.
FEMTOCLOCKS™CRYSTAL-TO-LVDS
FREQUENCY SYNTHESIZER W/INTEGRATED FANOUT BUFFER
TYPICAL PHASE NOISE
AT
125MHZ @ 3.3V
➤
0
-10
-20
Gb Ethernet Filter
-30
-40
125MHz
-50
RMS Phase Jitter (Random)
1.875MHz to 20MHz = 0.39ps (typical)
-60
-70
-80
-90
-100
Raw Phase Noise Data
-110
➤
NOISE POWER dBc
Hz
ICS844246
-120
-130
-140
➤
-150
-160
Phase Noise Result by adding
Gb Ethernet Filter to raw data
-170
-180
-190
1k
10k
100k
1M
10M
100M
OFFSET FREQUENCY (HZ)
844246AM
www.icst.com/products/hiperclocks.html
7
REV. A SEPTEMBER 29, 2005
PRELIMINARY
Integrated
Circuit
Systems, Inc.
ICS844246
FEMTOCLOCKS™CRYSTAL-TO-LVDS
FREQUENCY SYNTHESIZER W/INTEGRATED FANOUT BUFFER
PARAMETER MEASUREMENT INFORMATION
3.3V
2.5V
Qx
3.3V±5%
POWER SUPPLY
+ Float GND -
Qx
SCOPE
SCOPE
+ +
LVDS
LVDS
nQx
nQx
3.3V OUTPUT LOAD AC TEST CIRCUIT
3.3V/2.5V OUTPUT LOAD AC TEST CIRCUIT
nQx
nQ0:nQ5
Qx
Q0:Q5
t PW
t
nQy
Qy
odc =
tsk(o)
PERIOD
t PW
x 100%
t PERIOD
OUTPUT SKEW
OUTPUT DUTY CYCLE/PULSE WIDTH/PERIOD
VDD
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
➤
out
➤
LVDS
100
VOD/Δ VOD
out
➤
DC Input
DIFFERENTIAL OUTPUT VOLTAGE SETUP
844246AM
www.icst.com/products/hiperclocks.html
7
–
POWER
SUPPLY
Float GND
REV. A SEPTEMBER 29, 2005
PRELIMINARY
Integrated
Circuit
Systems, Inc.
ICS844246
FEMTOCLOCKS™CRYSTAL-TO-LVDS
FREQUENCY SYNTHESIZER W/INTEGRATED FANOUT BUFFER
APPLICATION INFORMATION
POWER SUPPLY FILTERING TECHNIQUES
As in any high speed analog circuitry, the power supply pins
are vulnerable to random noise. The ICS844246 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 V DDA pin. The 10Ω resistor
can also be replaced by a ferrite bead.
3.3V
VDD
.01μF
10Ω
V DDA
.01μF
10μF
FIGURE 1. POWER SUPPLY FILTERING
CRYSTAL INPUT INTERFACE
below were determined using an 18pF parallel resonant
crystal and were chosen to minimize the ppm error.
The ICS844246 has been characterized with 18pF parallel
resonant crystals. The capacitor values shown in Figure 2
XTAL_OUT
C1
22p
X1
18pF Parallel Crystal
XTAL_IN
C2
22p
Figure 2. CRYSTAL INPUt INTERFACE
844246AM
www.icst.com/products/hiperclocks.html
8
REV. A SEPTEMBER 29, 2005
PRELIMINARY
Integrated
Circuit
Systems, Inc.
ICS844246
FEMTOCLOCKS™CRYSTAL-TO-LVDS
FREQUENCY SYNTHESIZER W/INTEGRATED FANOUT BUFFER
RECOMMENDATIONS FOR UNUSED INPUT AND OUTPUT PINS
INPUTS:
OUTPUTS:
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.
LVDS
All unused LVDS output pairs can be either left floating or
terminated with 100Ω across. If they are left floating, we
recommend that there is no trace attached.
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.
2.5V or 3.3V
VDD
LVDS_Driv er
+
R1
100
-
100 Ohm Differential Transmission Line
FIGURE 3. TYPICAL LVDS DRIVER TERMINATION
844246AM
www.icst.com/products/hiperclocks.html
9
REV. A SEPTEMBER 29, 2005
PRELIMINARY
Integrated
Circuit
Systems, Inc.
ICS844246
FEMTOCLOCKS™CRYSTAL-TO-LVDS
FREQUENCY SYNTHESIZER W/INTEGRATED FANOUT BUFFER
RELIABILITY INFORMATION
TABLE 7A. θJAVS. AIR FLOW TABLE
FOR
24 LEAD SOIC
θJA by Velocity (Linear Feet per Minute)
Multi-Layer PCB, JEDEC Standard Test Boards
0
200
50°C/W
43°C/W
500
38°C/W
NOTE: Most modern PCB designs use multi-layered boards. The data in the second row pertains to most designs.
TABLE 7B. θJAVS. AIR FLOW TABLE
FOR
24 LEAD TSSOP
θJA by Velocity (Meters per Second)
Multi-Layer PCB, JEDEC Standard Test Boards
0
1
2.5
70°C/W
65°C/W
62°C/W
TRANSISTOR COUNT
The transistor count for ICS844246 is: 3887
844246AM
www.icst.com/products/hiperclocks.html
10
REV. A SEPTEMBER 29, 2005
PRELIMINARY
Integrated
Circuit
Systems, Inc.
PACKAGE OUTLINE - M SUFFIX
FEMTOCLOCKS™CRYSTAL-TO-LVDS
FREQUENCY SYNTHESIZER W/INTEGRATED FANOUT BUFFER
FOR
24 LEAD SOIC
PACKAGE OUTLINE - G SUFFIX
FOR
Millimeters
SYMBOL
Minimum
N
24 LEAD TSSOP
TABLE 8B. PACKAGE DIMENSIONS
TABLE 8A. PACKAGE DIMENSIONS
SYMBOL
Maximum
Millimeters
Minimum
N
24
Maximum
24
A
--
2.65
A
--
1.20
A1
0.10
--
A1
0.05
0.15
A2
2.05
2.55
A2
0.80
1.05
B
0.33
0.51
b
0.19
0.30
C
0.18
0.32
c
0.09
0.20
D
15.20
15.85
D
7.70
7.90
E
7.40
7.60
E
e
H
1.27 BASIC
E1
10.00
10.65
6.40 BASIC
4.30
e
4.50
0.65 BASIC
h
0.25
0.75
L
0.45
0.75
L
0.40
1.27
α
0°
8°
α
0°
8°
aaa
--
0.10
Reference Document: JEDEC Publication 95, MS-013, MO-119
844246AM
ICS844246
Reference Document: JEDEC Publication 95, MO-153
www.icst.com/products/hiperclocks.html
11
REV. A SEPTEMBER 29, 2005
PRELIMINARY
Integrated
Circuit
Systems, Inc.
ICS844246
FEMTOCLOCKS™CRYSTAL-TO-LVDS
FREQUENCY SYNTHESIZER W/INTEGRATED FANOUT BUFFER
TABLE 9. ORDERING INFORMATION
Part/Order Number
Marking
Package
Shipping Packaging
Temperature
ICS844246AM
TBD
24 Lead SOIC
tube
0°C to 70°C
ICS844246AMT
TB D
24 Lead SOIC
1000 tape & reel
0°C to 70°C
ICS844246AMLF
TBD
24 Lead "Lead-Free" SOIC
tube
0°C to 70°C
ICS844246AMLFT
TBD
24 Lead "Lead-Free" SOIC
1000 tape & reel
0°C to 70°C
ICS844246AG
ICS844246AG
24 Lead TSSOP
tube
0°C to 70°C
ICS844246AGT
ICS844246AG
24 Lead TSSOP
2500 tape & reel
0°C to 70°C
ICS844246AGLF
TBD
24 Lead "Lead-Free" TSSOP
tube
0°C to 70°C
ICS844246AGLFT
TBD
24 Lead "Lead-Free" TSSOP
2500 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 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.
844246AM
www.icst.com/products/hiperclocks.html
12
REV. A SEPTEMBER 29, 2005