ICS IS9108

AV9108
Integrated
Circuit
Systems, Inc.
CPU Frequency Generator
General Description
Features
The AV9108 offers a tiny footprint solution for generating two
simultaneous clocks. One clock, the REFCLK, is a fixed output
frequency which is the same as the input reference crystal (or
clock). The other clock, CLK1, can vary between 2 and 120
MHz, with up to 16 selectable preprogrammed frequencies
stored in internal ROM.
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•
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•
•
•
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The ICS9108 is ideal for use in a 3.3V system. It can generate
a 66.66 MHz clock at 3.3V. In addition, the ICS9108 provides
a symmetrical wave form with a worst case duty cycle of 45/55.
The ICS9108 has very tight edge control between the CPU
clock and 2XCPU clock outputs, with a worst case skew of
250ps.
The device has advanced features which include on-chip loop
filters, tristate outputs, and power-down capability. A minimum of external components - two decoupling capacitors and
an optional ferrite bead - are all that are required for jitter-free
operation. Standard versions for computer motherboard applications are the AV9108-03, AV9108-05 and the ICS9108-10.
Custom masked versions, with customized frequencies and
features, are available in 6-8 weeks for a small NRE fee.
Block Diagram
AV 9108 RevB032195
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•
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Runs up to 80 MHz at 3.3V
50/50 typical duty cycle at 5V
±250ps absolute jitter
Generates frequencies from 2 to 140 MHz
2 to 32 MHz input reference frequency
Up to 16 frequencies stored internally
Patented on-chip Phase Locked Loop with VCO for clock
generation
Provides reference clock and synthesized clock
On-chip loop filter
Low power 0.8µ CMOS technology
8-pin or 14-pin DIP or SOIC package
AV9108
Pin Configuration
FS0
1
8
REFCLK
GND
2
7
VDD
X1/ICLK
3
6
CLK1
X2
4
5
FS1
AV9108-05/-10
8-Pin DIP, SOIC
FS1
1
14
FS0
FS2
2
13
REFCLK
FS3
3
12
VDD
AGND
4
11
CLK1
GND
5
10
OE (CLK1)
PD
6
9
OE (REFCLK)
X1/ICLK
7
8
X2
AV9108-03/-11
14-Pin DIP, SOIC
Pin Descriptions for AV9108-03, AV9108-05 and AV9108-10
PIN NUMBER
PIN
NAME
TYPE
DESCRIPTION
-05/-10/-13
-03
1
5
14
1
2
FS0
FS1
FS2
Input
Input
Input
3
FS3
Input
Frequency Select 3 for CLK1 (-03 has pull-up).
4
5
6
7
AGND
GMD
PD
X1/ICLK
Input
Input
6
8
9
10
11
X2
OE(REFCLK)
OE(CLK1)
CLK1
Output
Input
Input
Output
Analog GROUND.
Digital GROUND.
POWER-DOWN. Shuts off chip when low. Internal pull-up.
CRYSTAL OUTPUT or INPUT CLOCK frequency. Typically 14.318 MHz
system clock.
CRYSTAL OUTPUT (No Connect when clock used.).
OUTPUT ENABLE. Tristates REFCLK when low. Pull-up.
OUTPUT ENABLE. Tristates CLK1 when low. Pull-up.
CLOCK1 Output (see decoding tables).
7
8
12
13
VDD
REFCLK
Output
2
3
4
Frequency Select 0 for CLK1 (-03 has pull-up).
Frequency Select 1 for CLK1 (-03 has pull-up).
Frequency Select 2 for CLK1 (-03 has pull-up).
Digital power supply (+3V DC).
REFERENCE CLOCK output. Produces a buffered version of the input clock or
crystal frequency (typically 14.318 MHz).
2
AV9108
Decoding Table for AV9108-11 (in MHz)
Actual Frequencies
Decoding Table for AV9108-05, 14.318 input
FS1
FS0
CLK1
0
0
1
1
0
1
0
1
40.01 MHz
50.11 MHz
66.61 MHz
80.01 MHz
Decoding Table for AV9108-03, 14.318 input
FS3
FS2
FS1
FS0
CLK1
0
0
0
1
0
0
0
0
1
1
1
1
1
1
1
1
0
0
0
0
1
1
1
1
0
0
0
0
1
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
1
0
1
0
1
0
1
16.00 MHz
39.99 MHz
50.11 MHz
80.01 MHz
66.58 MHz
100.23 MHz
8.02 MHz
4.01 MHz
8.02 MHz
20.00 MHz
25.06 MHz
40.01 MHz
33.29 MHz
50.11 MHz
4.01 MHz
2.05 MHz
FS3
FS2
FS1
FS0
CLK1
0
0
0
1
0
0
0
0
1
1
1
1
1
1
1
1
0
0
0
0
1
1
1
1
0
0
0
0
1
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
1
0
1
0
1
0
1
16.00 MHz
33.39 MHz
50.11 MHz
80.01 MHz
66.58 MHz
100.23 MHz
60.00 MHz
4.01 MHz
8.02 MHz
20.05 MHz
25.06 MHz
39.99 MHz
33.25 MHz
50.11 MHz
30.00 MHz
4.01 MHz
Decoding Table for AV9108-10, 14.318 input
FS1
FS0
CLK1
0
0
1
1
0
1
0
1
25.057 MHz
33.289 MHz
40.006 MHz
50.113 MHz
Note: The dash number following ICS9108 must be included when ordering product since it specifies the frequency decoding
table being ordered. Decoding options can be created by a simple metal mask change.
3
AV9108
Frequency Accuracy and Calculation
Allowable Input and Output Frequencies
The accuracy of the frequencies produced by the ICS9108
depends on the input frequency and the desired actual output
frequency. The formula for calculating the exact frequency is
as follows:
The input frequency should be between 2 and 32 MHz and the
A/B ratio should not exceed 24. The output should fall in the
range of 2-120 MHz.
Output Frequency = Input Frequency ×
A
B
Output Enable
The Output Enable feature tristates the specified output clock
pins. This places the selected output pins in a high impedance
state to allow for system level diagnostic testing.
where A=2, 3, 4 ... 128, and
B=2, 3, 4 ... 32.
For example, to calculate the actual output frequency for a
video monitor expecting a 44.900 MHz clock and using a
14.318 MHz input clock, the closest A/B ratio is 69/22, which
gives an output of 44.906 MHz (within 0.02% of the target
frequency). Generally, the ICS9108 can produce frequencies
within 0.1% of the desired output.
Power-Down
If equipped, the power-down shuts off the specified PLL or
entire chip to save current. A few milliseconds are required to
reach full functioning speed from a power-down state.
Frequency Transitions
A key ICS9108 feature is the ability to provide glitch-free frequency transitions across its output frequency range. The ICS9108
provides smooth transitions between any of the two groups of eight frequencies (when FS3=0 or FS3=1), so that the device will
switch glitch-free between 4-100 MHz and 2-50 MHz.
4
AV9108
Absolute Maximum Ratings
AVDD, VDD referenced to GND . . . . . . . . . . . . . . . 7V
Operating temperature under bias. . . . . . . . . . . . . . . . 0°C to +70°C
Storage temperature . . . . . . . . . . . . . . . . . . . . . . . . . . -65°C to +150°C
Voltage on I/O pins referenced to GND. . . . . . . . . . . GND -0.5V to VDD +0.5V
Power dissipation . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.5 Watts
Stresses above those listed under Absolute Maximum Ratings may cause permanent damage to the device. This is a stress rating
only and functional operation of the device at these or any other conditions above those indicated in the operational sections of
the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect product
reliability.
Electrical Characteristics at 5V
(Operating VDD = +4.5V to +5.5V; TA =0°C to 70°C unless otherwise stated)
DC Characteristics
PARAMETER
Input Low Voltage
Input High Voltage
Input Low Current
Input High Current
Output Low Voltage
Output High Voltage, Note 1
Output Low Current, Note 1
Output High Current, Note 1
Supply Current
Supply Current
Supply Current
Pull-up Resistor, Note 1
SYMBOL
VIL
VIH
IIL
IIH
VOL
VOH
IOL
IOH
ICC
ICC
(PD low)
ICC
(PD low)
Rpu
TEST CONDITIONS
MIN
TYP
MAX
UNITS
VIN=0V
VIN=VDD
IOL=10mA
IOH=-30mA
VOL=0.8V
VOH=2.0V
Unload, 50 MHz
Unload, Logic Inputs 000
2.0
-2.0
2.4
22.0
-
6.0
0.15
3.25
35.0
-50.0
18.0
38.0
0.8
16
2.0
0.40
-35.0
42.0
100.0
V
V
µA
µA
V
V
mA
mA
mA
µA
Unload, Logic Inputs 111
-
14.0
40.0
µA
-
380.0
700.0
k ohms
45.0
-
0.60
0.40
2.0
1.0
50.0
50.0
100.0
0.2
1.40
1.00
3.5
2.5
55.0
150.0
200.0
1.0
250.0
500.0
3.0
19.0
120.0
18.0
13.0
ns
ns
ns
ns
%
ps
ps
%
ps
ps
%
MHz
MHz
ms
ms
AC Characteristics
Rise Time 0.8 to 2.0V, Note 1
Fall Time 2.0 to 0.8V, Note 1
Rise Time 20% to 80%, Note 1
Fall Time 80% to 20%, Note 1
Duty Cycle, Note 1
Jitter, One Sigma, Note 1
Jitter, One Sigma, Note 1
Jitter, One Sigma, Note 1
Jitter, Absolute, Note 1
Jitter, Absolute, Note 1
Jitter, Absolute, Note 1
Input Frequency, Note 1
Output Frequency
Power-up Time, Note 1
Transition Time, Note 1
Tr
Tf
Tr
Tf
Dt
Tjis
Tjis
Tjis
Tjab
Tjab
Tjab
Fi
Fo
Tpu
Tft
15pf load
15pf load
15pf load
15pf load
15pf load @ 1.4V
From 20 to 100 MHz
From 14 to 16 MHz
From 14 to Below
From 20 to 100 MHz
From 14 to 16 MHz
From 14 to Below
-250.0
-500.0
11.0
2.0
-
8 to 66.6 MHz
1.0
14.3
7.58
6.0
Note 1: Parameter is guaranteed by design and characterization. Not 100% tested in production.
5
AV9108
Electrical Characteristics at 3.3V
(Operating VDD = +3.0V to +3.7V; TA =0°C to 70°C unless otherwise stated)
DC Characteristics
PARAMETER
Input Low Voltage
Input High Voltage
Input Low Current
Input High Current
Output Low Voltage
Output High Voltage
Output Low Current
Output High Current
Supply Current
Supply Current
Supply Current
Pull-up Resistor
SYMBOL
VIL
VIH
IIL
IIH
VOL
VOH
IOL
IOH
ICC
ICC
(PD low)
ICC
(PD low)
Rpu
TEST CONDITIONS
MIN
TYP
MAX
UNITS
VIN=0V
VIN=VDD
IOL=6mA
IOH=-5mA
VOL=0.2VDD
VOL=0.7VDD
Unloaded, 50 MHz
Unload, Logic Inputs 000
0.7VDD
-2.0
0.85
15.0
-
2.5
0.15
0.92
22.0
-17.0
22.0
13.0
0.20VDD
7.0
2.0
0.1
-10.0
40.0
40.0
V
V
µA
µA
V
V
mA
mA
mA
µA
Unload, Logic Inputs 111
-
4.0
12.0
µA
-
550.0
900.0
k ohms
40.0
-
2.2
1.2
46.0
50.0
100.0
0.4
3.5
2.5
60.0
150.0
200.0
1.0
250.0
500.0
3.0
15.3
90.0
18.0
13.0
ns
ns
%
ps
ps
%
ps
ps
%
MHz
MHz
ms
ms
AC Characteristics
Rise Time 20% to 80%, Note 1
Fall Time 80% to 20%
Duty Cycle
Jitter, One Sigma
Jitter, One Sigma
Jitter, One Sigma
Jitter, Absolute
Jitter, Absolute
Jitter, Absolute
Input Frequency
Output Frequency
Power-up Time, Note 1
Transition Time, Note 1
Tr
Tf
Dt
Tjis
Tjis
Tjis
Tjab
Tjab
Tjab
Fi
Fo
Tpu
Tft
15pf load
15pf load
15pf load @ 50%
From 25 to 85 MHz
From 14 to 20 MHz
From 14 to Below
From 25 to 85 MHz
From 14 to 20 MHz
From 14 to Below
-250.0
-500.0
13.3
2.0
-
8 to 66.6 MHz
Parameter is guaranteed by design and characterization.
6
1.0
14.3
7.58
6.0
AV9108
8-Pin DIP Package
14-Pin DIP Package
Ordering Information
AV9108-XXCN8, ICS9108-XXCN14
Example:
XXX XXXX- XX M X#W
Lead Count & Package Width
Lead Count=1, 2 or 3 digits
W=.3” SOIC or .6” DIP; None=Standard Width
Package Type
N=DIP (Plastic)
Pattern Number (2 or 3 digit number for parts with ROM code patterns)
Device Type (consists of 3 or 4 digit numbers)
Prefix
ICS, AV=Standard Device; GSP=Genlock Device
7
AV9108
8-Pin Plastic SOIC
14-Pin SOIC Package
Ordering Information
ICS9108-XXCS8, IS9108-XXCS14
Example:
XXX XXXX- XX M X#W
Lead Count & Package Width
Lead Count=1, 2 or 3 digits
W=.3” SOIC or .6” DIP; None=Standard Width
Package Type
S=SOIC
Pattern Number (2 or 3 digit number for parts with ROM code patterns)
Device Type (consists of 3 or 4 digit numbers)
Prefix
ICS, AV=Standard Device; GSP=Genlock Device
8