ICS5OSK481
MDS 5OSK481 B
1
Revision 111805
Integrated Circuit Systems, Inc.
525 Race Street, San Jose, CA 95126
tel (408) 297-1201
www.icst.com
48 MHz Tiny USB Clock Source
P R E L I M I N A R Y I N F O R M A T I O N
Description
The ICS5OSK481 is a low cost integrated clock
synthesizer solution designed for replacing crystals
and crystal oscillators.
The ICS5OSK481 generates a very accurate 48.00
MHz clock output.
Features
25 MHz clock input
The 48.00 MHz CLK output is USB2.0 reference
clock compliant
Output duty cycle 45/55% (worst case)
Advanced, low-power CMOS process
Industrial temperature range (-40 to +85
C)
Packaged in 5-pin TSOT
3.3 V supply voltage
Pb (lead) free package available
Short term C-C Jitter of 100 ps
Block Diagram
Clock
Buffer
PLL
ICLK
CLK
VDD
GND
OE
48 MHz Tiny USB Clock Source
MDS 5OSK481 B
2
Revision 111805
Integrated Circuit Systems, Inc.
525 Race Street, San Jose, CA 95126
tel (408) 297-1201
www.icst.com
P R E L I M I N A R Y I N F O R M A T I O N
ICS5OSK481
Pin Assignment
Pin Descriptions
External Components
Decoupling Capacitor
As with any high-performance mixed-signal IC, the
ICS5OSK481 must be isolated from system power
supply noise to perform optimally.
A decoupling capacitor of 0.01F must be connected
between each VDD and the PCB ground plane.
Series Termination Resistor
Clock output traces over one inch should use series
termination. To series terminate a 50
trace (a
commonly used trace impedance), place a 33
resistor
in series with the clock line, as close to the clock output
pin as possible. The nominal impedance of the clock
output is 20
.
PCB Layout Recommendations
For optimum device performance and lowest output
phase noise, the following guidelines should be
observed.
1) The 0.01F decoupling capacitors should be
mounted on the component side of the board as close
to the VDD pin as possible. No vias should be used
between the decoupling capacitors and VDD pins. The
PCB trace to VDD pins should be kept as short as
possible, as should the PCB trace to the ground via.
2) To minimize EMI, the 33
series termination resistor
(if needed) should be placed close to the clock output.
3) An optimum layout is one with all components on the
same side of the board, minimizing vias through other
signal layers. Other signal traces should be routed
away from the ICS5OSK481. This includes signal
traces just underneath the device, or on layers adjacent
to the ground plane layer used by the device.
O E
G N D
C L K
I C L K
1
2
3
5
4
V D D
Pin
Number
Pin
Name
Pin
Type
Pin Description
1
ICLK
Input
25 MHz clock input. Connect to a parallel resonant fundamental crystal or
input clock.
2
GND
Power
Connect to ground.
3
CLK
Output
PLL output clock. Internal pull-down resistor.
4
VDD
Power
Connect to 3.3 V.
5
OE
Input
Output Enable pin. Internal pull-up resistor. OE=0 outputs tristate with weak
pull-down.
48 MHz Tiny USB Clock Source
MDS 5OSK481 B
3
Revision 111805
Integrated Circuit Systems, Inc.
525 Race Street, San Jose, CA 95126
tel (408) 297-1201
www.icst.com
P R E L I M I N A R Y I N F O R M A T I O N
ICS5OSK481
Absolute Maximum Ratings
Stresses above the ratings listed below can cause permanent damage to the ICS5OSK481. These ratings,
which are standard values for ICS commercially rated parts, are stress ratings only. 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 can
affect product reliability. Electrical parameters are guaranteed only over the recommended operating
temperature range.
Recommended Operation Conditions
DC Electrical Characteristics
Unless stated otherwise, VDD=3.3 V 5%
, Ambient temperature -40 to +85
C, CL=15 pF
Item
Rating
Supply Voltage, VDD
7 V
All Inputs and Outputs
-0.5 V to VDD+0.5 V
Ambient Operating Temperature
-40 to +85
C
Storage Temperature
-65 to +150
C
Soldering Temperature
260
C
Parameter
Min.
Typ.
Max.
Units
Ambient Operating Temperature
-40
+85
C
Power Supply Voltage (measured in respect to GND)
+3.135
+3.465
V
Parameter
Symbol
Conditions
Min.
Typ.
Max.
Units
Operating Voltage
VDD
3.135
3.465
V
Input High Voltage, ICLK only
V
IH
ICLK
(VDD/2)+1
V
Input Low Voltage, ICLK only
V
IL
ICLK
(VDD/2)-1
V
Input High Voltage
V
IH
OE
2.0
V
Input Low Voltage
V
IL
OE
0.8
V
Output High Voltage
V
OH
I
OH
= -12 mA
2.4
V
Output Low Voltage
V
OL
I
OL
= 12 mA
0.4
V
IDD Operating Supply Current
No load
TBD
mA
Short Circuit Current
CLK output
+70
mA
On-Chip Pull-up Resistor
OE
270
k
Input Capacitance, S1, S0, and OE
4
pF
Nominal Output Impedance
20
48 MHz Tiny USB Clock Source
MDS 5OSK481 B
4
Revision 111805
Integrated Circuit Systems, Inc.
525 Race Street, San Jose, CA 95126
tel (408) 297-1201
www.icst.com
P R E L I M I N A R Y I N F O R M A T I O N
ICS5OSK481
AC Electrical Characteristics
Unless stated otherwise, VDD=3.3 V 5%
, Ambient temperature -40 to +85
C, CL=15 pF
Note 1: Measured with 15 pF load.
Parameter
Symbol
Conditions
Min.
Typ.
Max.
Units
Input Frequency, clock input
F
IN
0.5
25
MHz
Output Frequency, VDD = 3.3 V 5%
F
OUT
-40
C to +85C
48
MHz
Output Clock Rise Time
t
OR
0.8 to 2.0 V, Note 1
1
ns
Output Clock Fall Time
t
OF
2.0 to 8.0 V, Note 1
1
ns
Output Clock Duty Cycle
t
OD
1.5 V
45
49-51
55
%
Output Enable Time, OE high to
output on
50
ns
Output Disable Time, OE low to
tri-state
50
ns
Absolute Clock Period Jitter
t
ja
Deviation from
mean, Note 1
TBD
ps
48 MHz Tiny USB Clock Source
MDS 5OSK481 B
5
Revision 111805
Integrated Circuit Systems, Inc.
525 Race Street, San Jose, CA 95126
tel (408) 297-1201
www.icst.com
P R E L I M I N A R Y I N F O R M A T I O N
ICS5OSK481
Package Outline and Package Dimensions
(5-pin TSOT)
Package dimensions are kept current with JEDEC Publication No. 95
Ordering Information
Parts that are ordered with a "LF" suffix to the part number are the Pb-Free configuration and are RoHS compliant.
While the information presented herein has been checked for both accuracy and reliability, Integrated Circuit Systems (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.
Part / Order Number
Marking
Shipping Packaging
Package
Temperature
ICS5OSK481TILF
TBD
Tubes
5-pin TSOT
-40 to +85
C
ICS5OSK481TILFT
TBD
Tape and Reel
5-pin TSOT
-40 to +85
C
Millimeters
Symbol
Min
Max
A
--
1.00
A1
0.01
0.10
A2
0.84
0.90
b
0.30
0.45
c
0.12
0.20
D
2.90 BASIC
E
2.80 BASIC
E1
1.60 BASIC
e
0.95 BASIC
e1
1.90 BASIC
L
0.30
0.50
L1
0.60 REF
L2
0.25 BASIC
0
8
aaa
--
0.10
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