ICST AV9155C-36CM20 Low cost 20-pin frequency generator Datasheet

AV9155C
Integrated
Circuit
Systems, Inc.
Low Cost 20-Pin Frequency Generator
General Description
Features
The AV9155C is a low cost frequency generator designed
specifically for desktop and notebook PC applications with
either 3.3V or 5.0V power supply voltage. Its CPU clocks
provide all necessary CPU frequencies for 286, 386 and 486
systems, including support for the latest speeds of processors.
The device uses a 14.318 MHz crystal to generate the CPU
and all peripheral clocks for integrated desktop motherboards.
•
•
•
The dual 14.318 MHz clock outputs allows one output for the
system and one to be the input to an ICS graphics frequency
generator such as the AV9194.
The CPU clock offers the unique feature of smooth, glitchfree transitions from one frequency to the next, making this
ideal device to use whenever slowing the CPU speed. The
AV9155C makes a gradual transition between frequencies, so
that it obeys the Intel cycle-to-cycle timing specification for
486 systems. The simultaneous 2X and 1X CPU clocks offer
controlled skew to within 1.5ns (max) of each other.
ICS offers several versions of the AV9155C. The different
devices are shown below:
PART
•
•
•
•
•
•
Compatible with 286, 386, and 486 CPUs
Supports turbo modes
Generates communications clock, keyboard clock,
floppy disk clock, system reference clock, bus clock
and CPU clock
Output enable tristates outputs
Up to 100 MHz at 5V or 3.3V
20-pin DIP or SOIC
All loop filter components internal
Skew-controlled 2X and 1X CPU clocks
Power-down option
ICS has been shipping motherboard frequency generators
since April 1990, and is the leader in the area of multiple
output clocks on a single chip. The AV9155C is a third
generation device, and uses ICS’s patented analog CMOS
phase-locked loop technology for low phase jitter. ICS offers
a broad family of frequency generators for motherboards,
graphics and other applications, including cost-effective
versions with only one or two output clocks. Consult ICS for
all of your clock generation needs.
DESCRIPTION
AV9155C-01
Motherboard clock generator with 16 MHz BUS CLK
AV9155C-02
Motherboard clock generator with 32 MHz BUS CLK
AV9155C-23
Includes Pentium
AV9155C-36
Features a special 40 MHz SCSI clock
Ô frequencies
Block Diagram
Pentium is a trademark of Intel Corporation.
AV9155C Rev F 12/13/00
AV9155C
Pin Configuration
20-Pin DIP or SOIC
20-Pin DIP or SOIC
Pin Descriptions for AV9155C-01, -02
PIN
NUMBER
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
PIN NAME
1.843 MHz
X2
X1
VDD
GND
16 MHz/32 MHz
24 MHz
12 MHz
AGND
OE
FS2
PD#
14.318 MHz
14.318 MHz
GND
VDD
2XCPU
CPU
FS1
FS0
TYPE
Output
Output
Input
Output
Output
Output
Input
Input
Input
Output
Output
Output
Output
Input
Input
DESCRIPTION
1.84 MHz clock output.
Crystal connection.
Crystal connection.
Digital power supply (3.3V or 5.0V).
Digital Ground.
16 MHz (-01) or 32 MHz (-02) clock output.
24 MHz floppy disk/combination I/O clock output.
12 MHz keyboard clock output.
Analog ground (original version).
Output enable. Tristates all outputs when low. (Has internal pull-up.)
CPU clock frequency select #2. (Has internal pull-up.)
Power-down. Shuts off entire chip when low. (Has internal pull-up.)
14.318 MHz reference clock output.
14.318 MHz reference clock output.
Digital ground.
Digital power supply (3.3V or 5.0V).
2X CPU clock output.
1X CPU clock output.
CPU clock frequency select #1. (Has internal pull-up.)
CPU clock frequency select #0. (Has internal pull-up.)
2
AV9155C
Functionality - AV9155C-01
(Using 14.318 MHz input. All frequencies in MHz.)
PERIPHERAL CLOCKS
CLOCK#2 CPU and 2XCPU
FS2
(Pin 11)
FS1
(Pin 19)
FS0
(Pin 20)
2XCPU
(Pin 17)
CPU
(Pin 18)
COMMCLK
(Pin 1)
BUSCLK
(Pin 6)
FDCLK
(Pin 7)
KBCLK
(Pin 8)
0
0
0
0
1
1
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
8
16
32
40
50
66.66
80*
100*
4
8
16
20
25
33.33
40*
50*
1.843
16
24
12
REFERENCE CLOCKS
REFCLK1
(Pin 13)
REFCLK2
(Pin 14)
14.318
14.318
*VDD minimum 3.15V.
Functionality - AV9155C-02
(Using 14.318 MHz input. All frequencies in MHz.)
PERIPHERAL CLOCKS
CLOCK#2 CPU and 2XCPU
FS2
(Pin 11)
FS1
(Pin 19)
FS0
(Pin 20)
2XCPU
(Pin 17)
CPU
(Pin 18)
COMMCLK
(Pin 1)
BUSCLK
(Pin 6)
FDCLK
(Pin 7)
KBCLK
(Pin 8)
0
0
0
0
1
1
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
8
16
32
40
50
66.66
80*
100*
4
8
16
20
25
33.33
40*
50*
1.843
32
24
12
REFERENCE CLOCKS
* VDD minimum 3.15V
REFCLK1
(Pin 13)
REFCLK2
(Pin 14)
14.318
14.318
Frequency Transitions
Using an Input Clock as Reference
A key feature of the AV9155C is its ability to provide smooth,
glitch-free frequency transitions on the CPU and 2XCPU
clocks when the frequency select pins are changed. These
frequency transitions do not violate the Intel 486 specification
of less than 0.1% frequency change per clock period.
The AV9155C is designed to accept a 14.318 MHz crystal as
the input reference. With some external changes, it is possible
to use a crystal oscillator or clock input. Please see application
note AN04 for details on driving the AV9155C with a clock.
3
AV9155C
Pin Configuration
20-Pin DIP or SOIC
20-Pin DIP or SOIC
Pin Descriptions for AV9155C-23, -36
PIN
NUMBER
PIN
NAME
TYPE
DESCRIPTION
1
1.843/40 MHz
Output
1.84 MHz (-23)/40 MHz SCSI (-36) clock output.
2
X2
Output
Crystal connection.
Input
Crystal connection.
3
X1
4
VDD
-
Digital power supply (3.3V or 5.0V).
5
GND
-
Digital ground.
6
16 MHz/15 MHz
Output
16 MHz (-23)/15 MHz (-36) clock output.
7
24 MHz
Output
24 MHz floppy disk/combination I/O clock output.
12 MHz keyboard clock output.
8
12 MHz
Output
9
AGND
-
10
OE
Input
Output enable. Tristates all outputs when low. (Has internal pull-up.)
11
FS2
Input
CPU clock frequency select #2. (-23 has internal pull-up.)
12
PD#
Input
Power-down. Shuts off entire chip when low. (Has internal pull-up.)
Analog ground (original version).
13
14.318 MHz
Output
14.318 MHz reference clock output.
14
14.318 MHz
Output
14.318 MHz reference clock output.
15
GND
-
Digital ground.
16
VDD
17
2XCPU
Output
2X CPU clock output.
Digital power supply (3.3V or 5.0V).
1X CPU clock output.
18
CPU
Output
19
FS1
Input
CPU clock frequency select #1. (-23 has internal pull-up.)
20
FS0
Input
CPU clock frequency select #0. (-23 has internal pull-up.)
4
AV9155C
Functionality - AV9155C-23
(Using 14.318 MHz input. All frequencies in MHz.)
CLOCK#2 CPU and 2XCPU
PERIPHERAL CLOCKS
FS2
(Pin 11)
FS1
(Pin 19)
FS0
(Pin 20)
2XCPU
(Pin 17)
CPU
(Pin 18)
COMMCLK
(Pin 1)
BUSCLK (Pin
6)
FDCLK
(Pin 7)
KBCLK
(Pin 8)
0
0
0
0
1
1
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
75*
32
60
40
50
66.66
80*
52
37.5*
16
30
20
25
33.33
40*
26
1.843
16
24
12
REFERENCE CLOCKS
REFCLK1
(Pin 13)
REFCLK2
(Pin 14)
14.318
14.318
*VDD minimum 3.15V
Functionality - AV9155C-36
(Using 14.318 MHz input. All frequencies in MHz.)
CLOCK#2 CPU and 2XCPU
PERIPHERAL CLOCKS
FS2
(Pin 11)
FS1
(Pin 19)
FS0
(Pin 20)
2XCPU
(Pin 17)
CPU
(Pin 18)
SCSICLK
(Pin 1)
BUSCLK (Pin
6)
FDCLK
(Pin 7)
KBCLK
(Pin 8)
0
0
0
0
1
1
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
8
16
60
40
50
66.66
80*
100*
4
8
30
20
25
33.33
40*
50*
40
15
24
12
REFERENCE CLOCKS
*VDD minimum 3.15V
5
REFCLK1
(Pin 13)
REFCLK2
(Pin 14)
14.318
14.318
AV9155C
Absolute Maximum Ratings
VDD referenced to GND . . . . . . . . . . . . . . . . . . . . . . 7V
Voltage on I/O pins referenced to GND. . . . . . . . . . . GND -0.5V to VDD +0.5V
Operating temperature under bias. . . . . . . . . . . . . . . . 0°C to +70°C
Power dissipation . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.5 Watts
Storage temperature . . . . . . . . . . . . . . . . . . . . . . . . . . -40°C to +150°C
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
VDD = 4.0 to 5.5V (5V +10%/-20%); TA=0°C to 70°C unless otherwise stated
DC Characteristics
PARAMETER
Input Low Voltage
Input High Voltage
Input High Voltage, PD#
Input Low Current
SYMBOL
MIN
TYP
MAX
UNITS
VIL
VDD=5V
-
-
0.8
V
VIH
VDD=5V
2.0
-
-
V
VDD=5V, for PD# input
2.2
-
-
V
VIN=0V (pull-up pin)
-
16
35
µA
VIHPD
IIL
TEST CONDITIONS
Input High Current
IIH
VIN=VDD
-5
0
5
µA
Output Low Voltage
VOL
IOL=8mA
-
0.15
0.4
V
VOH
IOH=-25mA
2.4
3.7
-
V
IOL
VOL=0.8
15
32
-
mA
IOH
VOH=2.0V
-
-48
-30
mA
IDD
Unloaded, 66 MHz
-
38
60
mA
IDDPD
SCLKx=000 PD#=0
-
0.7
1.5
mA
With respect to typical
frequency
-
0.002
0.01
%
25
40
-
mA
-
-
10
pF
Output High Voltage
Output Low Current
Output High Current
1
1
1
Supply Current
Supply Current, Power-down
Output Frequency Change
over Supply and
Temperature 1
Short circuit current
Input Capacitance
1
Load Capacitance
1
Pull-up Resistor
1
1
FD
ISC
Each output clock
CI
Except X1, X2
CL
Pins X1, X2
Rpu
at VIN=VDD-1V
-
20
-
pF
120
350
700
k ohm
Notes:
1 Parameter is guaranteed by design and characterization, not subject to production testing.
6
AV9155C
Electrical Characteristics at 5V
VDD = 4.0 to 5.5V (5V +10%/-20%); TA=0°C to 70°C unless otherwise stated
AC Characteristics
PARAMETER
SYMBOL
Input Clock Rise Time 1
tICr
1
tICf
Input Clock Fall Time
1
Output Rise time
Rise time
1
Output Fall time
1
Fall time 1
TEST CONDITIONS
MIN
TYP
MAX
UNITS
-
-
20
ns
-
-
20
ns
tr
25pF load, 0.8 to 2.0V
-
1.5
2
ns
tr
25pF load, 20% to 80%
VDD
-
2.0
4.0
ns
tf
25pF load, 2.0 to 0.8V
-
1.0
2.0
ns
tf
25pF load, 80% to 20%
VDD
-
1.3
3.0
ns
1
dt
25pF load at 1.4V
45/55
48/52
55/45
%
1
Duty cycle, reference clocks
dt
25pF load at 1.4V
36
43
50
%
Jitter, one sigma 1 , 20 to 50
MHz clocks 1 on CPU and 40
to 100 MHz on 2XCPU
tjls1
10,000 cycles
-
0.8
2.0
%
Jitter, one sigma 1 , fixed
clock & clocks below 20
MHz on CPU, below 40 MHz
on 2XCPU
tjls2
10,000 cycles
-
0.8
2.0
%
Jitter, absolute 1 , 20 to 50
MHz clocks 1 on CPU and 40
to 100 MHz on 2XCPU
tjab1
10,000 cycles
-4.0
2.0
4.0
%
Jitter, absolute 1 , fixed clock
& clocks below 20 MHz on
CPU, below 40 MHz on
2XCPU
tjab2
10,000 cycles
-5.0
2.0
5.0
%
2
14.318
32
MHz
100
220
-
140
400
ps
to 66 MHz
-
8
15
ms
from 8 to 66.66 MH
-
6.5
12
ms
from 32 to 80 MHz
-
1.8
3.2
ms
from 80 to 32 MHz
-
2.5
5.0
ms
Duty cycle
Input Frequency
1
fin
Maximum Output
Frequency 1
fout
Clock skew between CPU and
2XCPU outputs 1
Tsk
Power-up Time
1
Frequency Transition Time
ttPO
1
tft
at 2XCPU
Notes:
1 Parameter is guaranteed by design and characterization, not subject to production testing.
7
MHz
AV9155C
Electrical Characteristics at 3.3V
VDD =3.0V to 3.7V, TA=0°C to 70°C unless otherwise stated
DC Characteristics
PARAMETER
SYMBOL
TEST CONDITIONS
MIN
TYP
MAX
UNITS
Input Low Voltage
VIL
VDD=3.3V
-
-
0.2VDD
V
Input High Voltage
VIH
VDD=3.3V
0.7VDD
-
-
V
2.2
-
-
V
Input High Voltage, PD#
VIHPD
VDD=3.3V, for PD# input
Input Low Current
IIL
VIN=0V (pull-up pin)
-
11
25
µA
Input High Current
IIH
VIN=VDD
-5
0
5
µA
V
Output Low Voltage
Output High Voltage
Output Low Current
Output High Current
1
1
1
Supply Current
Supply Current, Power-down
Output Frequency Change
over Supply and
Temperature 1
Short circuit current
1
VOL
IOL=4mA
-
0.05VDD
0.1VDD
VOH
IOH=-3.5mA
-
0.94VDD
-
V
IOL
VOL=0.2VDD
12
22
-
mA
IOH
VOH=0.7VDD
-
-11
-6.5
mA
IDD
Unloaded, 66.6 MHz
-
28
45
mA
IDDPD
SCLKx=000 PD#=0
-
0.25
0.5
mA
FD
With respect to typical
frequency
-
0.002
0.01
%
ISC
Each output clock
20
30
-
mA
Input Capacitance
1
CI
Except X1, X2
-
-
10
pF
Load Capacitance
1
CL
Pins X1, X2
-
20
-
pF
Rpu
at VIN=VDD-1V
120
330
650
k ohm
Pull-up Resistor 1
Notes:
1 Parameter is guaranteed by design and characterization, not subject to production testing.
8
AV9155C
Electrical Characteristics at 3.3V
VDD = +3.3V±10%, TA=0°C to 70°C unless otherwise stated
AC Characteristics
PARAMETER
Input Clock Rise Time
Input Clock Fall Time
SYMBOL
1
1
TEST CONDITIONS
MIN
TYP
MAX
UNITS
tICr
-
-
20
ns
tICf
-
-
20
ns
-
3.0
4.0
ns
Rise time 1
tr
25pF load, 20% to 80%
VDD
Fall time 1
tf
25pF load, 80% to 20%
VDD
-
1.8
2.5
ns
dt
25pF load at 50% VDD
40
48
60
%
25pF load at 50% VDD
Duty cycle
1
1
Duty cycle, reference clocks
Jitter, one sigma
Jitter, absolute
dt
1
1
Input Frequency
1
33
36
67
%
tjls1
10,000 cycles
-
0.8
2.5
%
tjab1
10,000 cycles
-5.0
2.0
5.0
%
2
14.318
32
Mhz
7
140
-
MHz
100
220
500
ps
to 66 MHz
-
6
12
ms
from 8 to 50.0 MHz
-
6
12
ms
fin
Maximum Output Frequency
1,2
fout
Clock skew between CPU and
2XCPU outputs 1
Tsk
Power-up Time 1
ttPO
Frequency Transition Time
1
tft
at 2XCPU
Notes:
1 Parameter is guaranteed by design and characterization, not subject to production testing.
2 Output frequencies on 2XCPU of 80 or 100 MHz require minimum VDD of 3.15V (3.3 -5%).
9
AV9155C
Actual Output Frequencies
(Using 14.318 MHz input. All frequencies in MHz.)
AV9155C-01 and AV9155C-02
CLOCK#2 CPU and 2XCPU
AV9155C-23
CPU CLOCK
FS2
(Pin 11)
FS1
(Pin 19)
FS0
(Pin 20)
2XCPU
(Pin 17)
CPU
(Pin 18)
FS2
(Pin 11)
FS1
(Pin 19)
FS0
(Pin 20)
2XCPU
(Pin 17)
CPU
(Pin 18)
0
0
0
0
1
1
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
7.50
15.51
32.22
40.09
50.11
66.82
80.18
100.23
3.75
7.76
16.11
20.05
25.06
33.41
40.09
50.11
0
0
0
0
1
1
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
75.170
31.940
60.136
40.090
50.113
66.476
80.181
51.903
37.585*
15.970
30.068
20.045
25.057
33.238
40.091
25.952
PERIPHERAL CLOCKS
PERIPHERAL CLOCKS
COMMCLK
(Pin 1)
BUSCLK (Pin
6)
FDCLK
(Pin 7)
KBCLK
(Pin 8)
COMMCLK
(Pin 1)
BUSCLK
(Pin 6)
FDCLK
(Pin 7)
KBCLK
(Pin 8)
1.846
32.01 or 16.00
24.00
12.00
1.846
16.00
24.00
12.00
AV9155C-36
CPU CLOCK
FS2
(Pin 11)
FS1
(Pin 19)
FS0
(Pin 20)
2XCPU
(Pin 17)
CPU
(Pin 18)
0
0
0
0
1
1
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
8.054
16.002
59.875
39.886
50.113
66.476
80.181
100.226
4.027
8.001
29.936
19.943
25.057
33.238
40.091
50.113
PERIPHERAL CLOCKS
COMMCLK
BUSCLK
(Pin 1)
(Pin 7)
40.00
15.00
FDCLK
(Pin 6)
KBCLK
(Pin 8)
24.00
12.00
10
AV9155C
AV9155C Recommended External Circuit
Notes:
1. ICS recommends the use of an isolated ground plane for the AV9155C. All grounds shown on this drawing should be
connected to this ground plane. This ground plane should be connected to the system ground plane at a single point. Please
refer to AV9155C Board Layout Diagram.
2. A single power supply connection for all VDD lines at the 2.2µF decoupling capacitor is recommended to reduce interaction
of analog and digital circuits. The 0.1µF decoupling capacitors should be located as close to each VDD pin as possible.
Ω series termination resistor should be used on any clock output which drives more than one load or drives a long trace
3. A 33Ω
(more than about two inches), especially when using high frequencies (>50 MHz). This termination resistor is put in series
with the clock output line close to the clock output. It helps improve jitter performance and reduce EMI by damping standing
waves caused by impedance mismatches in the output clock circuit trace.
4. The ferrite bead does not enhance the performance of the AV9155C, but will reduce EMI radiation from the VDD line.
11
AV9155C
AV9155C Recommended Board Layout
This is the recommended layout for the AV9155C to maximize clock performance. Shown are the power and ground
connections, the ground plane, and the input/output traces.
Use of the isolated ground plane and power connection, as shown, will prevent stray high frequency ground and system noise
from propagating through the device. When compared to using the system ground and power planes, this technique will
minimize output clock jitter. The isolated ground plane should be connected to the system ground plane at one point, near the
2.2µF decoupling cap. For lowest jitter performance, this isolated ground plane should be kept away from clock output pins
and traces. Keeping the isolated ground plane area as small as possible will minimize EMI radiation. Use a sufficient gap
between the isolated ground plane and system ground plane to prevent AC coupling. The ferrite bead in the VDD line optional,
but will help reduce EMI.
The traces to distribute the output clocks should be over a system ground or power supply plane. The trace width should be about
two times the thickness of the PC board between the trace and the underlying plane. These guidelines help minimize clock jitter
and EMI radiation. The traces to distribute power should be as wide as possible.
12
AV9155C
20-Pin DIP Package
Ordering Information
AV9155C-02CN20,
AV9155C-23CN20, AV9155C-36CN20
Example:
ICS XXXX-PPP 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#)
T&R=Tape and Reel
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
Notes:
Tape and reel packaging should be ordered with the suffix T&R. For instance, if the -01 in DIP and tape & reel is required,
order the part as AV9155C-01CN20T&R.
13
AV9155C
LEAD COUNT
14L
16L
18L
20L
24L
28L
32L
DIMENSION L
0.354
0.404
0.454
0.504
0.604
0.704
0.804
Ordering Information
AV9155C-01CW20, AV9155C-02CM20,
AV9155C-23CM20, AV9155C-36CM20
Example:
ICS XXXX-PPP 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
W=SOIC
T&R=Tape and Reel
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
14
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