ICS844246AMLF [ICSI]
FEMTOCLOCKS? CRYSTAL-TO-LVDS FREQUENCY SYNTHESIZER W/INTEGRATED FANOUT BUFFER; FEMTOCLOCKS ™ CRYSTAL - TO- LVDS频率合成W /综合扇出缓冲器
| 型号： | ICS844246AMLF |
| 厂家： | 
INTEGRATED CIRCUIT SOLUTION INC |
| 描述： | FEMTOCLOCKS? CRYSTAL-TO-LVDS FREQUENCY SYNTHESIZER W/INTEGRATED FANOUT BUFFER |
| 文件： | 总13页 (文件大小：186K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
PRELIMINARY
ICS844246
Integrated
Circuit
Systems, Inc.
FEMTOCLOCKS™ C RYSTAL-TO-LVDS
FREQUENCY SYNTHESIZER W/INTEGRATED FANOUT BUFFER
GENERAL DESCRIPTION
FEATURES
The ICS844246 is a Crystal-to-LVDS Clock • Six LVDS outputs
ICS
HiPerClockS™
Synthesizer/Fanout Buffer designed for Fibre
• Crystal oscillator interface
Channel and Gigabit Ethernet applications and
is a member of the HiperClockS™ family of
High Performance Clock Solutions from ICS.
• Output frequency range: 53.125MHz to 333.3333MHz
• Crystal input frequency range: 25MHz to 33.333MHz
The output frequency can be set using the frequency
select pins and a 25MHz crystal for Ethernet fre-
quencies, 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.
• 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
0
1
1
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
20
20
20
20
24
24
24
24
2
4
10
5
5
4
8
2.5
8
3
4
6
6
4
12
2
BLOCK DIAGRAM
PIN ASSIGNMENT
VDDO
VDDO
1
24
23
22
21
20
19
18
Q3
Q0
2
nQ3
3
nQ2
Q4
nQ0
4
Q2
nQ4
Pullup
PLL_BYPASS
nQ1
5
Q5
Q1
6
Q1
nQ5
7
8
9
10
11
12
nQ0
Q0
PLL_BYPASS
VDDA
N_SEL1
GND
GND
N_SEL0
XTAL_OUT
XTAL_IN
1
0
nQ1
17
16
15
14
13
Output
Divider
XTAL_IN
OSC
PLL
Q2
VDD
FB_SEL
XTAL_OUT
nQ2
ICS843246
24-Lead, 300-MIL SOIC
7.5mm x 15.33mm x 2.3mm
body package
Q3
Feedback
Divider
nQ3
M Package
TopView
Pulldown
FB_SEL
Q4
Pullup
nQ4
N_SEL1
24-LeadTSSOP
4.40mm x 7.8mm x 0.92mm
body package
Pullup
N_SEL0
Q5
G Package
TopView
nQ5
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
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REV.A SEPTEMBER 29, 2005
1
PRELIMINARY
ICS844246
Integrated
Circuit
Systems, Inc.
FEMTOCLOCKS™ C RYSTAL-TO-LVDS
FREQUENCY SYNTHESIZER W/INTEGRATED FANOUT BUFFER
TABLE 1. PIN DESCRIPTIONS
Number
1, 2
Name
VDDO
Type
Description
Power
Output
Output
Output
Output supply pins.
3, 4
nQ2, Q2
nQ1, Q1
nQ0, Q0
Differential output pair. LVDS interface levels.
Differential output pair. LVDS interface levels.
5, 6
7, 8
Differential output pair. LVDS interface levels.
Selects between the PLL and crystal inputs as the input to the dividers.
9
PLL_BYPASS
Input
Pullup
When LOW, selects PLL. When HIGH, selects XTAL_IN, XTAL_OUT.
LVCMOS / LVTTL interface levels.
10
11
12
VDDA
VDD
Power
Power
Analog supply pin.
Core supply pin.
FB_SEL
Input Pulldown Feedback frequency select pin. LVCMOS/LVTTL interface levels.
13,
14
15,
18
XTAL_IN,
XTAL_OUT
N_SEL0
Crystal oscillator interface. XTAL_IN is the input.
XTAL_OUT is the output.
Input
Input
Pullup
Output frequency select pin. LVCMOS/LVTTL interface levels.
N_SEL1
16, 17
19, 20
21, 22
23, 24
GND
Power supply ground.
nQ5, Q5
nQ4, Q4
nQ3, Q3
Output
Output
Output
Differential output pair. LVDS interface levels.
Differential output pair. LVDS interface levels.
Differential output pair. LVDS interface levels.
NOTE: Pullup and Pulldown refer to internal input resistors. See Table 2, Pin Characteristics, for typical values.
TABLE 2. PIN CHARACTERISTICS
Symbol
CIN
Parameter
Test Conditions
Minimum Typical Maximum Units
Input Capacitance
Input Pullup Resistor
4
pF
kΩ
kΩ
RPULLUP
51
51
RPULLDOWN Input Pulldown Resistor
844246AM
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REV.A SEPTEMBER 29, 2005
2
PRELIMINARY
ICS844246
Integrated
Circuit
Systems, Inc.
FEMTOCLOCKS™ C RYSTAL-TO-LVDS
FREQUENCY SYNTHESIZER W/INTEGRATED FANOUT BUFFER
CRYSTAL FUNCTION TABLE
Inputs
Function
XTAL (MHz) FB_SEL N_SEL1 N_SEL0
M
20
20
20
20
24
24
24
24
20
24
24
24
24
20
20
20
20
20
20
20
20
20
20
20
20
VCO (MHz)
500
N
2
Output (MHz)
250
25
25
0
0
0
0
1
1
1
1
0
1
1
1
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
1
0
0
1
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
0
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
500
4
125
25
500
5
100
25
500
8
62.5
25
600
3
200
25
600
4
150
25
600
6
100
25
600
12
5
50
26.5625
26.5625
26.5625
26.5625
26.5625
30
531.25
637.5
637.5
637.5
637.5
600
106.25
212.5
159.375
106.25
53.125
300
3
4
6
12
2
30
600
4
150
30
600
5
120
30
600
8
75
31.25
31.25
31.25
31.25
33.3333
33.3333
33.3333
33.3333
625
2
312.5
156.25
125
625
4
625
5
625
8
78.125
333.3333
166.6667
133.3333
83.3333
666.6667
666.6667
666.6667
666.6667
2
4
5
8
844246AM
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REV.A SEPTEMBER 29, 2005
3
PRELIMINARY
ICS844246
Integrated
Circuit
Systems, Inc.
FEMTOCLOCKS™ C RYSTAL-TO-LVDS
FREQUENCY SYNTHESIZER W/INTEGRATED FANOUT BUFFER
ABSOLUTE MAXIMUM RATINGS
SupplyVoltage, V
4.6V
NOTE: Stresses beyond those listed under Absolute
Maximum Ratings may cause permanent damage to the
DD
Inputs, V
-0.5V to VDD + 0.5V
I
device.These ratings are stress specifications only.Functional
operation of product at these conditions or any conditions be-
yond 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.
Outputs, IO
Continuous Current
Surge Current
10mA
15mA
PackageThermal Impedance, θ
24 Lead SOIC
24 LeadTSSOP
JA
50°C/W (0 lfpm)
70°C/W (0 mps)
StorageTemperature, T
-65°C to 150°C
STG
TABLE 4A. POWER SUPPLY DC CHARACTERISTICS, VDD = VDDA = VDDO = 3.3V 5ꢀ, TA = 0°C TO 70°C
Symbol Parameter
Test Conditions
Minimum
3.135
Typical
3.3
Maximum Units
VDD
VDDA
VDDO
IDD
Core Supply Voltage
3.465
3.465
3.465
V
V
Analog Supply Voltage
Output Supply Voltage
Power Supply Current
Analog Supply Current
Output Supply Current
3.135
3.3
3.135
3.3
V
125
7
mA
mA
mA
IDDA
IDDO
127
TABLE 4B. POWER SUPPLY DC CHARACTERISTICS, VDD = VDDA = 3.3V 5ꢀ, VDDO = 2.5V 5ꢀ, TA = 0°C TO 70°C
Symbol Parameter
Test Conditions
Minimum
3.135
Typical
3.3
Maximum Units
VDD
VDDA
VDDO
IDD
Core Supply Voltage
3.465
3.465
2.625
V
V
Analog Supply Voltage
Output Supply Voltage
Power Supply Current
Analog Supply Current
Output Supply Current
3.135
3.3
2.375
2.5
V
125
7
mA
mA
mA
IDDA
IDDO
115
TABLE 4C. LVCMOS / LVTTL DC CHARACTERISTICS, VDD = VDDA = 3.3V 5ꢀ, VDDO = 3.3V 5ꢀ OR 2.5V 5ꢀ, TA = 0°C TO 70°C
Symbol Parameter
Test Conditions
Minimum Typical Maximum Units
VIH
VIL
Input High Voltage
2
VDD + 0.3
0.8
V
V
Input Low Voltage
-0.3
FB_SEL
VDD = VIN = 3.465V
150
µA
IIH
Input High Current
PLL_BYPASS,
N_SEL0, N_SEL1
V
DD = VIN = 3.465V
VDD = 3.465V, VIN = 0V
DD = 3.465V, VIN = 0V
5
µA
µA
µA
FB_SEL
-5
IIL
Input Low Current
PLL_BYPASS,
N_SEL0, N_SEL1
V
-150
844246AM
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REV.A SEPTEMBER 29, 2005
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PRELIMINARY
ICS844246
Integrated
Circuit
Systems, Inc.
FEMTOCLOCKS™ C RYSTAL-TO-LVDS
FREQUENCY SYNTHESIZER W/INTEGRATED FANOUT BUFFER
TABLE 4D. LVDS DC CHARACTERISTICS, VDD = VDDA = VDDO = 3.3V 5ꢀ TA = 0°C TO 70°C
Symbol Parameter Test Conditions Minimum
Typical
387
Maximum Units
VOD
Differential Output Voltage
mV
mV
V
Δ VOD
VOS
VOD Magnitude Change
Offset Voltage
40
1.29
50
Δ VOS
VOS Magnitude Change
mV
NOTE: Please refer to Parameter Measurement Information for output information.
TABLE 4E. LVDS DC CHARACTERISTICS, VDD = VDDA = 3.3V 5ꢀ, VDDO = 2.5V 5ꢀ, TA = 0°C TO 70°C
Symbol
VOD
Parameter
Test Conditions
Minimum
Typical
379
Maximum Units
Differential Output Voltage
VOD Magnitude Change
Offset Voltage
mV
mV
V
Δ VOD
VOS
40
1.24
50
Δ VOS
VOS Magnitude Change
mV
TABLE 5. CRYSTAL CHARACTERISTICS
Parameter
Test Conditions
Minimum Typical Maximum Units
Mode of Oscillation
Frequency
Fundamental
25
33.333
MHz
Ω
Equivalent Series Resistance (ESR)
Shunt Capacitance
Drive Level
50
7
pF
1
mW
NOTE: Characterized using an 18pf parallel resonant crystal.
844246AM
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REV.A SEPTEMBER 29, 2005
5
PRELIMINARY
ICS844246
Integrated
Circuit
Systems, Inc.
FEMTOCLOCKS™ C RYSTAL-TO-LVDS
FREQUENCY SYNTHESIZER W/INTEGRATED FANOUT BUFFER
TABLE 6A. AC CHARACTERISTICS, VDD =VDDA = VDDO = 3.3V 5ꢀ, TA = 0°C TO 70°C
Symbol Parameter
Test Conditions
Minimum Typical Maximum Units
FOUT
Output Frequency
53.125
333.33
MHz
125MHz, Integration Range:
1.875MHz - 20MHz
tjit(Ø)
RMS Phase Jitter (Random)
0.39
ps
tsk(o)
tR / tF
odc
Output Skew; NOTE 1, 2
Output Rise/Fall Time
Output Duty Cycle
PLL Lock Time
TBD
355
50
ps
ps
ꢀ
20ꢀ to 80ꢀ
tLOCK
1
ms
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.
TABLE 6B. AC CHARACTERISTICS, VDD =VDDA = 3.3V 5ꢀ, VDDO = 2.5V 5ꢀ, TA = 0°C TO 70°C
Symbol Parameter
Test Conditions
Minimum Typical Maximum Units
FOUT
Output Frequency
53.125
333.33
MHz
125MHz, Integration Range:
1.875MHz - 20MHz
tjit(Ø)
RMS Phase Jitter (Random)
0.38
ps
tsk(o)
tR / tF
odc
Output Skew; NOTE 1, 2
Output Rise/Fall Time
Output Duty Cycle
PLL Lock Time
TBD
380
50
ps
ps
ꢀ
20ꢀ to 80ꢀ
tLOCK
1
ms
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
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REV.A SEPTEMBER 29, 2005
6
PRELIMINARY
ICS844246
Integrated
Circuit
Systems, Inc.
FEMTOCLOCKS™ C RYSTAL-TO-LVDS
FREQUENCY SYNTHESIZER W/INTEGRATED FANOUT BUFFER
TYPICAL PHASE NOISE AT 125MHZ @ 3.3V
0
-10
-20
-30
-40
Gb Ethernet Filter
125MHz
RMS Phase Jitter (Random)
1.875MHz to 20MHz = 0.39ps (typical)
-50
-60
-70
-80
-90
-100
-110
-120
-130
-140
Raw Phase Noise Data
-150
-160
-170
-180
-190
Phase Noise Result by adding
Gb Ethernet Filter to raw data
1k
10k
100k
1M
10M
100M
OFFSET FREQUENCY (HZ)
844246AM
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REV.A SEPTEMBER 29, 2005
7
PRELIMINARY
ICS844246
Integrated
Circuit
Systems, Inc.
FEMTOCLOCKS™ C RYSTAL-TO-LVDS
FREQUENCY SYNTHESIZER W/INTEGRATED FANOUT BUFFER
PARAMETER MEASUREMENT INFORMATION
3.3V
2.5V
SCOPE
Qx
SCOPE
Qx
+ +
–
3.3V 5ꢀ
POWER SUPPLY
LVDS
POWER
SUPPLY
Float GND
LVDS
+
Float GND
-
nQx
nQx
3.3V OUTPUT LOAD AC TEST CIRCUIT
3.3V/2.5V OUTPUT LOAD AC TEST CIRCUIT
nQ0:nQ5
nQx
Qx
Q0:Q5
tPW
tPERIOD
nQy
tPW
Qy
odc =
x 100ꢀ
tsk(o)
tPERIOD
OUTPUT SKEW
OUTPUT DUTY CYCLE/PULSE WIDTH/PERIOD
VDD
out
80ꢀ
tF
80ꢀ
➤
DC Input
LVDS
VSWING
20ꢀ
Clock
20ꢀ
Outputs
out
VOS/Δ VOS
tR
➤
OFFSET VOLTAGE SETUP
OUTPUT RISE/FALL TIME
VDD
➤
out
LVDS
DC Input
100
V
OD/Δ VOD
➤
out
DIFFERENTIAL OUTPUT VOLTAGE SETUP
844246AM
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REV.A SEPTEMBER 29, 2005
7
PRELIMINARY
ICS844246
Integrated
Circuit
Systems, Inc.
FEMTOCLOCKS™ C RYSTAL-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 VDDA pin. The 10Ω resistor
can also be replaced by a ferrite bead.
3.3V
VDD
.01μF
.01μF
10Ω
VDDA
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
XTAL_IN
C1
22p
X1
18pF Parallel Crystal
C2
22p
Figure 2. CRYSTAL INPUt INTERFACE
844246AM
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REV.A SEPTEMBER 29, 2005
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PRELIMINARY
ICS844246
Integrated
Circuit
Systems, Inc.
FEMTOCLOCKS™ C RYSTAL-TO-LVDS
FREQUENCY SYNTHESIZER W/INTEGRATED FANOUT BUFFER
RECOMMENDATIONS FOR UNUSED INPUT AND OUTPUT PINS
INPUTS:
OUTPUTS:
LVCMOS CONTROL PINS:
LVDS
All control pins have internal pull-ups or pull-downs; additional All unused LVDS output pairs can be either left floating or
resistance is not required but can be added for additional terminated with 100Ω across. If they are left floating, we
protection. A 1kΩ resistor can be used.
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 require a matched load termination of 100Ω across near
differential transmission line environment, LVDS drivers 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
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REV.A SEPTEMBER 29, 2005
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PRELIMINARY
ICS844246
Integrated
Circuit
Systems, Inc.
FEMTOCLOCKS™ C RYSTAL-TO-LVDS
FREQUENCY SYNTHESIZER W/INTEGRATED FANOUT BUFFER
RELIABILITY INFORMATION
TABLE 7A. θJAVS. AIR FLOW TABLE FOR 24 LEAD SOIC
θJA byVelocity (Linear Feet per Minute)
0
200
43°C/W
500
38°C/W
Multi-Layer PCB, JEDEC Standard Test Boards
50°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 byVelocity (Meters per Second)
0
1
2.5
Multi-Layer PCB, JEDEC Standard Test Boards
70°C/W
65°C/W
62°C/W
TRANSISTOR COUNT
The transistor count for ICS844246 is: 3887
844246AM
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REV.A SEPTEMBER 29, 2005
10
PRELIMINARY
ICS844246
Integrated
Circuit
Systems, Inc.
FEMTOCLOCKS™ C RYSTAL-TO-LVDS
FREQUENCY SYNTHESIZER W/INTEGRATED FANOUT BUFFER
PACKAGE OUTLINE - M SUFFIX FOR 24 LEAD SOIC
PACKAGE OUTLINE - G SUFFIX FOR 24 LEAD TSSOP
TABLE 8B. PACKAGE DIMENSIONS
TABLE 8A. PACKAGE DIMENSIONS
Millimeters
SYMBOL
Millimeters
SYMBOL
Minimum
Maximum
Minimum
Maximum
N
A
24
N
A
24
--
2.65
--
--
1.20
0.15
1.05
0.30
0.20
7.90
A1
A2
B
0.10
2.05
0.33
0.18
15.20
7.40
A1
A2
b
0.05
0.80
0.19
0.09
7.70
2.55
0.51
0.32
15.85
7.60
C
D
E
c
D
E
6.40 BASIC
0.65 BASIC
e
1.27 BASIC
E1
e
4.30
4.50
H
h
10.00
0.25
0.40
0°
10.65
0.75
1.27
8°
L
0.45
0°
0.75
8°
L
α
α
aaa
--
0.10
Reference Document: JEDEC Publication 95, MS-013, MO-119
Reference Document: JEDEC Publication 95, MO-153
844246AM
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REV.A SEPTEMBER 29, 2005
11
PRELIMINARY
ICS844246
Integrated
Circuit
Systems, Inc.
FEMTOCLOCKS™ C RYSTAL-TO-LVDS
FREQUENCY SYNTHESIZER W/INTEGRATED FANOUT BUFFER
TABLE 9. ORDERING INFORMATION
Part/Order Number
ICS844246AM
Marking
Package
Shipping Packaging Temperature
TBD
TBD
24 Lead SOIC
tube
1000 tape & reel
tube
0°C to 70°C
0°C to 70°C
0°C to 70°C
0°C to 70°C
0°C to 70°C
0°C to 70°C
0°C to 70°C
0°C to 70°C
ICS844246AMT
ICS844246AMLF
ICS844246AMLFT
ICS844246AG
24 Lead SOIC
TBD
24 Lead "Lead-Free" SOIC
24 Lead "Lead-Free" SOIC
24 Lead TSSOP
TBD
1000 tape & reel
tube
ICS844246AG
ICS844246AG
TBD
ICS844246AGT
ICS844246AGLF
ICS844246AGLFT
24 Lead TSSOP
2500 tape & reel
tube
24 Lead "Lead-Free" TSSOP
24 Lead "Lead-Free" TSSOP
TBD
2500 tape & reel
NOTE: Parts that are ordered with an "LF" suffix to the part 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
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REV.A SEPTEMBER 29, 2005
12
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