ICS650-21 [ICSI]
System Peripheral Clock Source; 系统外设时钟源
| 型号： | ICS650-21 |
| 厂家： | 
INTEGRATED CIRCUIT SOLUTION INC |
| 描述： | System Peripheral Clock Source |
| 文件： | 总4页 (文件大小：66K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
PRELIMINARY INFORMATION
ICS650-21
System Peripheral Clock Source
Description
Features
The ICS650-21 is a low cost, low jitter, high
performance clock synthesizer for system
• Packaged in 20 pin tiny SSOP (QSOP)
• Lower jitter version of ICS650-01
• Operating VDD of 3.3V or 5V
• Zero ppm synthesis error in all clocks
• Inexpensive 25 MHz crystal or clock input
• Provides Ethernet and Fast Ethernet clocks
• Provides SCSI clocks
peripheral applications. Using analog/digital
Phase-Locked Loop (PLL) techniques, the device
accepts a parallel resonant 25 MHz crystal input to
produce up to eight output clocks. The device
provides clocks for PCI, SCSI, Fast Ethernet,
Ethernet, USB, and AC97. The user can select one
of three USB frequencies, and also one of two
AC97 audio frequencies. The OE pin puts all
outputs into a high impedance state for board level
testing. All frequencies are generated with less than
one ppm error, meeting the demands of SCSI and
Ethernet clocking.
• Provides PCI clocks
• Selectable AC97 audio clock
• Selectable USB clock
• OE pin tri-states the outputs for testing
• Selectable frequencies on three clocks
• Duty cycle of 45/55 for Processor clock and Audio
clock
The ICS650 can be mask customized to produce
any frequencies from 1 to 150 MHz.
Block Diagram
• Advanced, low power CMOS process
Processor Clocks
(Fast Ethernet,
SCSI, PCI )
3
Output
Buffer
2
PSEL1:0
Output
Buffer
ASEL
Audio Clock
Clock
Synthesis
Circuitry
Output
Buffers
USEL
USB Clock
25 MHz
crystal
or clock
X1/ICLK
Output
Buffers
20 MHz
25 MHz
Crystal
Oscillator
Output
Buffer
X2
Output Enable (all outputs)
MDS 650-21 A
1
Revision 010301
Integrated Circuit Systems, Inc. • 525 Race Street • San Jose •CA•95126• (408) 295-9800tel • www.icst.com
PRELIMINARY INFORMATION
ICS650-21
System Peripheral Clock Source
Pin Assignment
Processor Clock (MHz)
PSEL1 PSEL0
PCLK1
25.00
37.5
66.66
40.00
33.3334
20.00
20.00
20.00
PCLK2,3
50.00
75.00
133.33
80.00
66.6667
40.00
PSEL1
USEL
1
2
3
4
5
6
7
20
0
0
0
0
M
1
19 PSEL0
18 PCLK2
X2
X1/ICLK
VDD
M
M
M
1
0
M
1
PCLK3
VDD
17
16
0
33.3334
66.6667
VDD
1
M
1
1
50
100
GND
15
14
13
12
11
ASEL
USB Clock (MHz)
USEL
UCLK
Audio Clock (MHz)
GND
ASEL
ACLK
49.152
24.576
14.318
UCLK
20M
ACLK
25M
8
OFF/14.318M
PCLK1
OE
0
M
1
0
M
1
12
9
24
48
10
0 = connect directly to ground, 1 = connect directly
to VDD, M=leave unconnected (floating)
20 pin (150 mil) SSOP
Pin Descriptions
Pin #
Name
USEL
X2
X1/ICLK
VDD
VDD
GND
UCLK
20M
ACLK
25M
Type Description
1
2
3
4
5
6
7
I
XO
XI
P
P
P
UCLK Select pin. Determines frequency of USB clock per table above.
Crystal connection. Connect to parallel mode 25 MHz crystal. Leave open for clock.
Crystal connection. Connect to parallel mode 25 MHz crystal, or clock.
Connect to VDD. Must be same value as other VDD. Decouple with pin 6.
Connect to VDD. Must be same value as other VDD.
Connect to ground.
O
O
O
O
I
USB clock output per table above.
Fixed 20 MHz output for Ethernet.
AC97 Audio clock output per table above.
Fixed 25 MHz reference output for Fast Ethernet.
Output Enable. Tri-states all outputs when low.
8
9
10
11
12
13
14
15
16
17
18
19
20
OE
PCLK1
OFF/14.318M
GND
O
O
P
PCLK output number 1 per table above.
14.31818 MHz clock output only when ASEL=VDD.
Connect to ground.
ASEL
VDD
PCLK3
PCLK2
PSEL0
PSEL1
I
P
O
O
I
ACLK Select pin. Determines frequency of Audio clock per table above.
Connect to VDD. Must be same value as other VDD. Decouple with pin 14.
PCLK output number 3 per table above.
PCLK output number 2 per table above.
Processor Select pin #0. Determines frequencies on PCLKs 1-3 per table above.
Processor Select pin #1. Determines frequencies on PCLKs 1-3 per table above.
I
Key: I = Input; XO/XI = crystal connections; O = output; P = power supply connection
MDS 650-21 A
2
Revision 010301
Integrated Circuit Systems, Inc. • 525 Race Street • San Jose •CA•95126• (408) 295-9800tel • www.icst.com
PRELIMINARY INFORMATION
ICS650-21
System Peripheral Clock Source
Electrical Specifications
Parameter
Conditions
Minimum
Typical
Maximum Units
ABSOLUTE MAXIMUM RATINGS (note 1)
Supply voltage, VDD
Referenced to GND
7
VDD+0.5
70
V
V
C
C
C
Inputs and Clock Outputs
Ambient Operating Temperature
Soldering Temperature
Storage temperature
Referenced to GND
Max of 10 seconds
-0.5
0
260
-65
150
DC CHARACTERISTICS (VDD = 3.3V or 5V unless noted)
Operating Voltage, VDD
3.0
2
5.5
0.8
0.4
V
V
Input High Voltage, VIH
Input Low Voltage, VIL
Output High Voltage, VOH
Output Low Voltage, VOL
Select inputs, OE
Select inputs, OE
V
VDD=3.3V, IOH=-8mA
VDD=3.3V, IOL=8mA
2.4
V
V
Output High Voltage, VOH, VDD = 3.3 or 5V IOH=-8mA
VDD-0.4
V
Operating Supply Current, IDD, at 5V
Operating Supply Current, IDD, at 3.3V
Short Circuit Current, VDD = 3.3
Input Capacitance
No Load, note 2
No Load, note 2
Each output
50
30
±50
5
mA
mA
mA
pF
Except X1
AC CHARACTERISTICS (VDD = 3.3V or 5V unless noted)
Input Crystal or Clock Frequency
25.000
MH z
ppm
ns
Output Clocks Accuracy (synthesis error)
Output Clock Rise Time
All clocks
1
0.8 to 2.0V
2.0 to 0.8V
At VDD/2
At VDD/2
1.5
1.5
60
55
Output Clock Fall Time
ns
Output Clock Duty Cycle, UCLCK
Output Clock Duty Cycle, PCLCK, ACLCK
One Sigma Jitter, except ACLK
One Sigma Jitter, ACLK
40
45
50
50
%
%
75
ps
120
ps
Absolute Clock Period Jitter PCLK, UCLK, 20M
- 500
500
ps
Notes: 1. Stresses beyond those listed under Absolute Maximum Ratings could cause permanent damage to the device. Prolonged
exposure to levels above the operating limits but below the Absolute Maximums may affect device reliability.
2. With all clocks at highest frequencies.
External Components
The ICS650 requires a minimum number of external components for proper operation. Decoupling
capacitors of 0.1µF should be connected between VDD and GND (on pins 4 and 6, and pins 16 and 14),
as close to the chip as possible. A series termination resistor of 33Wmay be used for each clock output. The
25.000 MHz crystal must be connected as close to the chip as possible. The crystal should be a fundamental
mode, parallel resonant, 30ppm or better (to meet the Ethernet specs). Crystal capacitors should be
connected from pins X1 to ground and X2 to ground. The value of these capacitors is given by the
following equation, where C is the crystal load capacitance: Crystal caps (pF) = (C -12) x 2. So for a
L
L
crystal with 16pF load capacitance, two 8pF caps should be used. If a clock input is used, drive it into X1
and leave X2 unconnected.
MDS 650-21 A
3
Revision 010301
Integrated Circuit Systems, Inc. • 525 Race Street • San Jose •CA•95126• (408) 295-9800tel • www.icst.com
PRELIMINARY INFORMATION
ICS650-21
System Peripheral Clock Source
Package Outline and Package Dimensions
(For current dimensional specifications, see JEDEC Publication No. 95.)
20 pin SSOP
Inches
Symbol Min
Millimeters
Max
Min
1.35
0.10
0.20
0.18
8.55
Max
A
A1
b
0.053 0.069
0.004 0.010
0.008 0.012
0.007 0.010
0.337 0.344
.025 BSC
1.75
0.25
0.30
0.25
8.75
E1
E
c
D
e
0.635 BSC
INDEX
AREA
E
0.228 0.244
0.150 0.157
0.016 0.050
5.80
3.80
0.40
6.20
1
2
E1
L
4.00
1.27
D
A
A1
c
b
L
e
Ordering Information
Part/Order Number
ICS650R-21
Marking
Package
Shipping
Tubes
Temperature
0 to 70° C
ICS650R-21
ICS650R-21
ICS650R-21I
ICS650R-21I
20 pin SSOP
20 pin SSOP
20 pin SSOP
20 pin SSOP
ICS650R-21T
ICS650R-21I
Tape and Reel 0 to 70° C
Tubes -40 to 85° C
Tape and Reel -40 to 85° C
ICS650R-21IT
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 the 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.
MDS 650-21 A
4
Revision 010301
Integrated Circuit Systems, Inc. • 525 Race Street • San Jose •CA•95126• (408) 295-9800tel • www.icst.com
相关型号：
©2020 ICPDF网 联系我们和版权申明