IDT ICS5OSK482TILF Schematic [ru]

PRELIMINARY DATASHEET

48 MHZ USB CLOCK SOURCE ICS5OSK482

Description

The ICS5OSK482 is a low cost integrated clock synthesizer solution designed for replacing crystals and crystal oscillators.

The ICS5OSK482 generates a very accurate 48.00 MHz clock output.

Block Diagram

VDD

Crystal

Oscillator

Features

• 14.31818 MHz crystal 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

PLL CLK

External capacitors are required with a crystal input.

GND

IDT™ / ICS™

48 MHZ USB CLOCK SOURCE 1

ICS5OSK482 REV B 110805

ICS5OSK482 48 MHZ USB CLOCK SOURCE SYNTHESIZERS

Pin Assignment

GND

CLK

VDD

Pin Descriptions

Number

1 X1 Input 14.31818 MHz crystal input. Connect to a parallel resonant fundamental crystal.

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 X2 Output 14.31818 MHz crystal output.

Name

Typ e

Pin Description

External Components

External Crystal

The ICS5OSK482 requires a 14.31818 MHz crystal. In order to minimize ppm errors, the PCB should include pads for crystal capacitors from pins X1 to ground and X2 to ground to optimize the initial accuracy. The capacitor value can be determined by tuning the PCB so that the error on the reference output is equal to the initial crystal error.

Crystal Load Capacitors

The device crystal connections should include pads for small capacitors from pins X1 to ground and X2 to ground. These capacitors are used to adjust the stray capacitance of the board to match the nominally required crystal load capacitance. Because load capacitance can only be increased in this trimming process, it is important to keep stray capacitance to a minimum by using very short PCB traces (and no vias) between the crystal and device. Crystal capacitors must be connected from each of the pins X1 and X2 to ground.

The value (in pF) of these crystal caps should equal (C pF) * 2. In the equation, C

= crystal load capacitance in pF.

Example: For a crystal with a 8 pF load capacitance, each crystal capacitor would be 4 pF [(8-6) x 2 = 4].

IDT™ / ICS™

48 MHZ USB CLOCK SOURCE 2

-6

ICS5OSK482 REV B 110805

ICS5OSK482 48 MHZ USB CLOCK SOURCE SYNTHESIZERS

Absolute Maximum Ratings

Stresses above the ratings listed below can cause permanent damage to the ICS5OSK482. 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

Output High Voltage V

Output Low Voltage V

IDD Operating Supply Current IDD No Load TBD mA

Short Circuit Current I

Input Capacitance C

Nominal Output Impedance 20 Ω

= -12 mA 2.4 V

= 12 mA 0.4 V

CLK output ±70 mA

4pF

IDT™ / ICS™

48 MHZ USB CLOCK SOURCE 3

ICS5OSK482 REV B 110805

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