ICS661_技术文档

DATASHEET

PRECISION AUDIO CLOCK SOURCE

ICS661

Description

Features

The ICS661 provides synchronous clock generation for

audio sampling clock rates derived from an MPEG stream,

or can be used as a standalone clock source with a 27 MHz

crystal. The device uses the latest PLL technology to

provide excellent phase noise and long term jitter

• Packaged in 16-pin TSSOP

• Available in Pb (lead) fere package

• Clock or crystal input

• Low phase noise

• Low jitter

performance for superior synchronization and S/N ratio.

• Exact (0 ppm) multiplication ratios

• Reference clock output available

• Support for 256, 384, 512, and 768 times sampling rate

Please contact IDT if you have a requirement for an input

and output frequency not included here - we can rapidly

modify this product to meet special requirements.

Block Diagram

VDD (P2)

VDD (P3)

VDDO

VDDR

X2

REF

Crystal

Oscillator

X1/REFIN

SELIN

PLL Clock

CLK

Synthesis

S3:0

4

GND (P13)

GND (P6) GND (P5)

IDT™ / ICS™ PRECISION AUDIO CLOCK SOURCE

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ICS661

REV D 111804

ICS661

PRECISION AUDIO CLOCK SOURCE

CLOCK SYNTHESIZER

Pin Assignment

Output Clock Selection Table

Input

Frequency

(MHz)

Output

Frequency

(MHz)

S3

S2

S1

S0

X1/REFIN

VDD

S0

1

2

3

4

5

6

7

8

16

15

14

13

12

11

10

9

X2

REF

VDDR

GND

SELIN

VDDO

S1

0

1

0

1

0

1

0

1

0

1

0

1

0

1

0

1

0

1

0

1

0

1

0

1

0

1

0

1

0

1

27

8.192

11.2896

12.288

24.576

12.288

16.9344

18.432

36.864

16.384

22.5792

24.576

49.152

24.576

33.8688

36.864

73.728

GND

S3

S2

CLK

16-pin 4.40 mil body, 0.50 mm pitch TSSOP

Pin Descriptions

Number

Name

Type

Pin Description

Connect this pin to a crystal or clock input

1

2

X1/REFIN

VDD

S0

Input

Power Power supply for crystal oscillator.

Power Power supply for PLL.

3

4

Input

Output frequency selection. Determines output frequency per table above. On chip pull-up.

5

GND

S3

Power Connect to ground.

6

Power Ground for output stage.

7

Input

Output frequency selection. Determines output frequency per table above. On chip pull-up.

8

S2

9

CLK

S1

Output Clock output.

10

11

12

13

14

15

16

Input

Output frequency selection. Determines output frequency per table above. On chip pull-up.

VDDO

SELIN

GND

VDDR

REF

X2

Power Power supply for output stage.

Input

Low for clock input, high for crystal. On chip pull-up.

Power Connect to ground.

Power Power supply for reference output. Ground to turn off REF.

Output Reference clock output.

Input

Connect this pin to a crystal. Leave open if using a clock input.

IDT™ / ICS™ PRECISION AUDIO CLOCK SOURCE

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ICS661

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ICS661

PRECISION AUDIO CLOCK SOURCE

CLOCK SYNTHESIZER

Application Information

capacitance of the board to match the nominally required

crystal load capacitance. To reduce possible noise pickup,

use very short PCB traces (and no vias) been the crystal

and device.

Series Termination Resistor

Clock output traces should use series termination. To series

terminate a 50Ωtrace (a commonly used trace impedance),

place a 33Ωresistor in series with the clock line, as close to

the clock output pin as possible. The nominal impedance of

the clock output is 20Ω.

The value of the load capacitors can be roughly determined

by the formula C = 2(C - 6) where C is the load capacitor

L

connected to X1 and X2, and C is the specified value of the

L

Decoupling Capacitors

load capacitance for the crystal. A typical crystal C is 18 pF,

L

As with any high performance mixed-signal IC, the ICS661

must be isolated from system power supply noise to perform

optimally.

so C = 2(18 - 6) = 24 pF. Because these capacitors adjust

the stray capacitance of the PCB, check the output

frequency using your final layout to see if the value of C

should be changed.

Decoupling capacitors of 0.01µF must be connected

between each VDD and the PCB ground plane. To further

guard against interfering system supply noise, the ICS661

should use one common connection to the PCB power

plane as shown in the diagram on the next page. The ferrite

bead and bulk capacitor help reduce lower frequency noise

in the supply that can lead to output clock phase modulation.

PCB Layout Recommendations

For optimum device performance and lowest output phase

noise, the following guidelines should be observed.

1) Each 0.01µF decoupling capacitor should be mounted on

the component side of the board as close to the VDD pin as

possible. No vias should be used between decoupling

capacitor and VDD pin. The PCB trace to VDD pin should

be kept as short as possible, as should the PCB trace to the

ground via. Distance of the ferrite bead and bulk decoupling

from the device is less critical.

Recommended Power Supply Connection for

Optimal Device Performance

VDD Pin

Ferrite

Bead

Connection to 3.3V

VDD Pin

2) The external crystal should be mounted next to the device

with short traces. The X1 and X2 traces should not be

routed next to each other with minimum spaces, instead

they should be separated and away from other traces.

Power Plane

Bulk Decoupling Capacitor

(such as 1 F Tantalum)

VDD Pin

3) To minimize EMI and obtain the best signal integrity, the

33Ω series termination resistor should be placed close to

the clock output.

0.01 F Decoupling Capacitors

4) An optimum layout is one with all components on the

same side of the board, minimizing vias through other signal

layers (the ferrite bead and bulk decoupling capacitor can be

mounted on the back). Other signal traces should be routed

away from the ICS661. This includes signal traces just

underneath the device, or on layers adjacent to the ground

plane layer used by the device.

All power supply pins must be connected to the same

voltage, except VDDR and VDDO may be connected to a

lower voltage in order to change the output level. If the

reference output is not used, ground VDDR.

Crystal Load Capacitors

If a crystal is used, the device crystal connections should

include pads for capacitors from X1 to ground and from X2

to ground. These capacitors are used to adjust the stray

IDT™ / ICS™ PRECISION AUDIO CLOCK SOURCE

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ICS661

REV D 111804

ICS661

PRECISION AUDIO CLOCK SOURCE

CLOCK SYNTHESIZER

Absolute Maximum Ratings

Stresses above the ratings listed below can cause permanent damage to the ICS661. These ratings, which are

standard values for IDT 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

Supply Voltage, VDD

All Inputs and Outputs

5.5 V

-0.5 V to VDD+0.5 V

-40 to +85° C

-65 to +150° C

125°C

Ambient Operating Temperature

Storage Temperature

Junction Temperature

Soldering Temperature

260°C

Recommended Operation Conditions

Parameter

Min.

Typ.

Max.

+85

Units

° C

Ambient Operating Temperature

Power Supply Voltage (measured in respect to GND)

-40

+3.0

+3.6

V

DC Electrical Characteristics

Unless stated otherwise, VDD = 3.3 V ±10%, Ambient Temperature -40 to +85°C

Parameter

Symbol

VDD

Conditions

Min.

3.0

1.8

2

Typ.

Max. Units

Operating Voltage

3.6

V

VDDO

VDDR

VDD

V

Input High Voltage

Input Low Voltage

V

IH

V

0.8

0.4

V

IL

Output High Voltage

Output Low Voltage

Supply Current

V

I

= -4 mA

= -20 mA

= 20 mA

VDD-0.4

2.4

V

OH

OL

V

OL

IDD

No Load

25

±65

20

mA

Ω

Short Circuit Current

Nominal Output Impedance

Input Capacitance

I

Each output

OS

Z

OUT

Input pins

7

pF

kΩ

Internal Pull-up Resistor

120

IDT™ / ICS™ PRECISION AUDIO CLOCK SOURCE

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ICS661

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ICS661

PRECISION AUDIO CLOCK SOURCE

CLOCK SYNTHESIZER

AC Electrical Characteristics

Unless stated otherwise, VDD = 3.3 V ±10%, Ambient Temperature -40 to +85°C

Parameter

Crystal Frequency

Output Clock Rise Time

Output Clock Fall Time

Output Duty Cycle

Jitter, Short term

Symbol

Conditions

Min.

Typ.

Max. Units

27

28

1.5

55

MHz

ns

t

20% to 80%, 15 pF load

80% to 20%, 15 pF load

At VDD/2, 15 pF load

Reference clock off

OR

t

ns

OF

t

45

49 to 51

175

%

OD

ps p-p

Jitter, Short term

Reference clock on

175

Reference clock off; 10

us delay

Jitter, Long term

300

ps p-p

dBc

Reference clock on; 10

us delay

Single Sideband Phase

Noise

Reference clock off; 10

kHz offset

-110

Single Sideband Phase

Noise

Reference clock on; 10

kHz offset

-110

0

dBc

Actual Mean Frequency

Error versus Target

ppm

Thermal Characteristics

Parameter

Symbol

Conditions

Min.

Typ. Max. Units

Thermal Resistance Junction to

Ambient

θ

Still air

78

70

68

37

° C/W

JA

JC

1 m/s air flow

3 m/s air flow

Thermal Resistance Junction to Case

IDT™ / ICS™ PRECISION AUDIO CLOCK SOURCE

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ICS661

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ICS661

PRECISION AUDIO CLOCK SOURCE

CLOCK SYNTHESIZER

Package Outline and Package Dimensions (16-pin TSSOP, 4.40 mm Body, 0.65 mm Pitch)

Package dimensions are kept current with JEDEC Publication No. 95, MO-153

16

Millimeters

Min Max

Inches

Max

Symbol

Min

--

A

A1

A2

b

--

1.20

0.15

1.05

0.30

0.20

5.1

0.047

0.006

0.041

0.012

0.05

0.80

0.19

0.09

4.90

0.002

0.032

0.007

E1

E

INDEX

AREA

C

0.0035 0.008

0.193 0.201

0.252 BASIC

0.169 0.177

0.0256 Basic

D

1 2

E

6.40 BASIC

4.30 4.50

0.65 Basic

E1

e

D

L

0.45

0.75

0.018

0.030

α

0°

8°

0°

8°

aaa

--

0.10

--

0.004

A

A2

A1

c

- C -

e

SEATING

PLANE

b

L

aaa C

Ordering Information

Part / Order Number

ICS661GI

Marking

ICS661GI

661GILF

Shipping Packaging

Tubes

Package

Temperature

-40 to +85°C

16-pin TSSOP

ICS661GIT

Tape and Reel

Tubes

ICS661GILF

ICS661GILFT

Tape and Reel

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 Device Technology (IDT) 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 IDT. IDT reserves the right to change any circuitry or specifications without notice. IDT

does not authorize or warrant any IDT product for use in life support devices or critical medical instruments.

IDT™ / ICS™ PRECISION AUDIO CLOCK SOURCE

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ICS661

REV D 111804

ICS661

PRECISION AUDIO CLOCK SOURCE

CLOCK SYNTHESIZER

Innovate with IDT and accelerate your future networks. Contact:

www.IDT.com

For Sales

800-345-7015

408-284-8200

Fax: 408-284-2775

For Tech Support

www.idt.com/go/clockhelp

Corporate Headquarters

Integrated Device Technology, Inc.

www.idt.com

Technology, Inc. Accelerated Thinking is a service mark of Integrated Device Technology, Inc. All other brands, product names and marks are or may be trademarks or registered

trademarks used to identify products or services of their respective owners.

Printed in USA


型号：	ICS661
厂家：	INTEGRATED DEVICE TECHNOLOGY
描述：	PRECISION AUDIO CLOCK SOURCE Precision音频时钟源时钟
文件：	总7页 (文件大小：179K)
中文：	中文翻译
下载：	下载PDF数据表文档文件

ICS661 [IDT]

相关型号：

ICS661GI

ICS661GI

ICS661GILF

ICS661GILF

ICS661GILFT

ICS661GILFTR

ICS661GIT

ICS661GITR

ICS662-02

ICS662-03

ICS66203

ICS662M-02