IDT ICS5OSK481TILF Schematic [ru]

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48 MHZ USB CLOCK SOURCE ICS5OSK481

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.

Block Diagram

VDD

Clock
Buffer

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

PLLICLK CLK

IDT™ / ICS™

GND

48 MHZ USB CLOCK SOURCE 1

OE

ICS5OSK481 REV B 110805

ICS5OSK481
48 MHZ USB CLOCK SOURCE SYNTHESIZERS

Pin Assignment

OE

ICLK

1

5

GND

CLK

2

VDD

3

4

Pin Descriptions

Pin

Number

1 ICLK Input 25 MHz clock input.

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

Pin

Name

Pin

Typ e

Pin Description

pull-down.

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.

should be kept as short as possible, as should the PCB
trace to the ground via.

2) To minimize EMI, the 33Ω series termination resistor (if
needed) should be placed close to the clock output.

A decoupling capacitor of 0.01µF 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 50Ω trace (a commonly
used trace impedance), place a 33Ω resistor in series with
the clock line, as close to the clock output pin as possible.
The nominal impedance of the clock output is 20Ω.

PCB Layout Recommendations

For optimum device performance and lowest output phase
noise, the following guidelines should be observed.

1) The 0.01µF 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

IDT™ / ICS™

48 MHZ USB CLOCK SOURCE 2

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.

ICS5OSK481 REV B 110805

ICS5OSK481
48 MHZ USB CLOCK SOURCE SYNTHESIZERS

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.

Item Rating

Max Supply Voltage, VDD 7 V

Logic Inputs -0.5 V to VDD+0.5 V

Ambient Operating Temperature -40 to +85°C

Storage Temperature -65 to +150°C

Junction Temperature 125°C

Soldering Temperature 260°C

Recommended Operation Conditions

Parameter Min. Typ. Max. Units

Ambient Operating Temperature -40 +85 °C

Power Supply Voltage (measured in respect to GND) +3.135 +3.3 +3.465 V

DC Electrical Characteristics

VDD=3.3 V ±5%, Ambient temperature -40 to +85°C, CL = 15 pF, unless stated otherwise

Parameter Symbol Conditions Min. Typ. Max. Units

Operating Voltage VDD 3.135 3.465 V

Input High Voltage, ICLK only V

Input Low Voltage, ICLK only V

Input High Voltage V

Input Low Voltage V

Output High Voltage V

Output Low Voltage V

IDD Operating Supply Current IDD No Load TBD mA

Short Circuit Current I

Internal Pull-up Resistor R

Input Capacitance, ICLK, OE C

Nominal Output Impedance 20 Ω

OH

OL

OS

PU

ICLK VDD/2+1 V

IH

ICLK VDD/2-1 V

IL

OE 2.0 V

IH

OE 0.8 V

IL

I

= -12 mA 2.4 V

OH

I

= 12 mA 0.4 V

OL

CLK output ±50 mA

OE 270 kΩ

OE, select pins 4 pF

IN

IDT™ / ICS™

48 MHZ USB CLOCK SOURCE 3

ICS5OSK481 REV B 110805

ICS5OSK481
48 MHZ USB CLOCK SOURCE SYNTHESIZERS

AC Electrical Characteristics

VDD = 3.3 V ±5%, Ambient Temperature -40 to +85°C, CL = 15 pF, unless stated otherwise

Parameter Symbol Conditions Min. Typ. Max. Units

Input Clock Frequency, clock input f

Output Frequency f

Output Clock Rise Time t

Output Clock Fall Time t

Output Clock Duty Cycle t

IN

OUT

OR

OF

DC

0.8 to 2.0 V, Note 1 1 ns

2.0 to 0.8 V, Note 1 1 ns

1.5 V 45 50 60 %

Output Frequency Error 0 ppm

Output Enable Time, OE high to
output on

Output Disable Time, OE low to
tri-state

Absolute Clock Period Jitter t

JA

Deviation from mean, Note 1 100 ps

Note 1: Measured with a 15 pF load.

0.5 25 MHz

48 MHz

50 ns

50 ns

IDT™ / ICS™

48 MHZ USB CLOCK SOURCE 4

ICS5OSK481 REV B 110805

ICS5OSK481
48 MHZ USB CLOCK SOURCE SYNTHESIZERS

Package Outline and Package Dimensions (5-pin TSOT)

Package dimensions are kept current with JEDEC Publication No. 95

Millimeters

Symbol Min Max

A — 1.00
A1 0.01 0.10
A2 0.84 0.90

b0.300.45

c0.120.20
D 2.90 BASIC
E 2.80 BASIC

E1 1.60 BASIC

e 0.95 BASIC

e1 1.90 BASIC

L0.300.50

L1 0.60 REF
L2 0.25 BASIC

θ

aaa — 0.10

0° 8°

Ordering Information

Part / Order Number Marking Shipping Packaging Package Temperature

ICS5OSK481TILF 1TIL Tubes 5-pin TSOT -40 to +85° C

ICS5OSK481TILFT 1TIL Tape and Reel 5-pin TSOT -40 to +85° C

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.

IDT™ / ICS™

48 MHZ USB CLOCK SOURCE 5

ICS5OSK481 REV B 110805

ICS5OSK481
48 MHZ USB CLOCK SOURCE SYNTHESIZERS

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