MK2049-45ASILFTR Datasheet MK2049-45ASILFTR, MK2049-45ASILF | P1-P3

DATASHEET

3.3 VOLT COMMUNICATIONS CLOCK PLL MK2049-45A

IDT™

3.3 VOLT COMMUNICATIONS CLOCK PLL 1

MK2049-45A REV C 051310

Description

The MK2049-45A is a dual Phase-Locked Loop (PLL)

device which can provide frequency synthesis and jitter

attenuation. The first PLL is VCXO based and uses a

pullable crystal to track signal wander and attenuate input

jitter. The second PLL is a translator for frequency

multiplication. Basic configuration is determined by a

Mode/Frequency Selection Table. Loop bandwidth and

damping factor are programmable via external loop filter

component selection.

Buffer Mode accepts a 10 to 50 MHz input and will provide

a jitter attenuated output at 0.5 x ICLK, 1 x ICLK or 2 x

ICLK. In this mode the MK2049-45A is ideal for filtering jitter

from high frequency clocks.

In External Mode, ICLK accepts an 8 kHz clock and will

produce output frequencies from a table of common

communciations clock rates, CLK and CLK/2. This allows

for the generation of clocks frequency-locked to an 8 kHz

backplane clock, simplifying clock synchronization in

communications systems.

The MK2049-45A can be dynamically switched between T1,

E1, T3, E3 outputs with the same 24.576 MHz crystal.

IDT can customize these devices for many other different

frequencies. Contact your IDT representative for more

details.

Features

• Packaged in 20-pin SOIC

• 3.3 V + 5% operation

• Meets the TR62411, ETS300 011, and GR-1244

specification for MTIE, Pull-in/Hold-in Range, Phase

Transients, and Jitter Generation for Stratum 3, 4, and 4E

• Accepts multiple inputs: 8 kHz backplane clock, or 10 to

50 MHz

• Locks to 8 kHz + 100 ppm (External mode)

• Buffer Mode allows jitter attenuation of 10 - 50 MHz input

and x1 / x0.5 or x1 / x2 outputs

• Exact internal ratios enable zero ppm error

• Output rates include T1, E1, T3, E3, and OC3

submultiples

• Pb (lead) free package

• See also the MK2049-34 and MK2049-36

Block Diagram

Charge

Pump

VCXO

X2X1ISET CAP2

Feedback

Divider (N)

Reference

Divider

(used in buffer

mode only)

ICLK

Reference

Divider

Phase

Detector

VCXO

PLL

Feedback

Divider

VCO

Translator

PLL

CLK

CAP1

Output

Divider

Divide

by 2

CLK/2

SET

Optional Crystal Load Caps

Divider Value

Look-up Table

FS3:0

External Pullable Crystal

MK2049-45A

3.3 VOLT COMMUNICATIONS CLOCK PLL VCXO AND SYNTHESIZER

IDT™

3.3 VOLT COMMUNICATIONS CLOCK PLL 2

MK2049-45A REV C 051310

Pin Assignment

Pin Descriptions

FS1 FS0

RES

VDD

CAP2

FCAP

VDD

GND

CAP1

VDD

GND

CLK

ICLK

CLK/2

FS3

FS2

Number

Name

Type

Pin Description

1 FS1 Input Frequency select 1. Determines CLK input/outputs per table on page 2.

Internal pull-up resistor.

2 X2 Input Crystal connection. Connect to a MHz crystal as shown in table on page 2.

3 X1 Input Crystal connection. Connect to a MHz crystal as shown in table on page 2.

4 VDD Power Power supply. Connect to +3.3 V.

5 FCAP - Filter capacitor. Connect a 1000 pF ceramic capacitor to ground.

6 VDD Power Power supply. Connect to +3.3 V.

7 GND Power Connect to ground

8 CLK Output Clock output determined by status of FS3:0 per tables on page 2.

9 CLK/2 Output Clock output determined by status of FS3:0 per tables page 2. Always 1/2 of

CLK.

10 8k Output Recovered 8 kHz clock output.

11 FS2 Input Frequency select 2. Determines CLK input/outputs per table on page 2.

Internal pull-up resistor.

12 FS3 Input Frequency select 3. Determines CLK input/outputs per table on page 2.

Internal pull-up resistor.

13 ICLK Input Input clock connection. Connect to 8 kHz backplane or MHz clock.

14 GND Power Connect to ground.

15 VDD Power Power Supply. Connect to +3.3 V.

16 CAP1 Loop

Filter

Connect the loop filter capacitors and resistor between this pin and CAP2.

17 GND Power Connect to ground.

MK2049-45A

3.3 VOLT COMMUNICATIONS CLOCK PLL VCXO AND SYNTHESIZER

IDT™

3.3 VOLT COMMUNICATIONS CLOCK PLL 3

MK2049-45A REV C 051310

Output Decoding Table - External Mode (MHz)

Output Decoding Table - Buffer Mode (MHz)

0 = connect directly to ground, 1 = connect directly to VDD

Crystal is connected to pins 2 and 3; clock input is applied to pin 13.

Functional Description

The MK2049-45A is a clock generator IC that generates an

output clock directly from an internal VCXO circuit which

works in conjunction with an external quartz crystal. The

VCXO is controlled by an internal PLL (Phase Locked Loop)

circuit, enabling the device to perform clock regeneration

from an input reference clock. The MK2049-45A is

configured to provide a high frequency communications

reference clock output from an 8 kHz input clock or to jitter

attenuate and buffer a high frequency input clock. There are

14 selectable output frequencies and two buffer mode

selections. Please refer to the Output Clock Selection Table

on Page 2.

Most typical PLL clock devices use an internal VCO (Voltage

Controlled Oscillator) for output clock generation. By using

a VCXO with an external crystal, the MK2049-45A is able to

18 CAP2 Loop

Filter

Connect the loop filter capacitors and resistor between this pin and CAP1.

19 RES - Connect a resistor to ground. See table.

20 FS0 Input Frequency select 0. Determines CLK input/outputs per table on page 2.

Internal pull-up resistor.

ICLK FS3 FS2 FS1 FS0 CLK/2 CLK 8k

Crystal

Used (MHz) N

8 kHz00001.5443.0888 kHz24.576 3072

8 kHz00012.0484.0968 kHz24.576 3072

8 kHz001022.36844.7368 kHz24.576 3072

8 kHz001117.18434.3688 kHz24.576 3072

8 kHz010019.4438.888 kHz 19.44 2430

8 kHz0101 12.8 25.6 8 kHz 25.6 3200

8 kHz011025.9251.848 kHz 17.28 2160

8 kHz01114.0968.1928 kHz16.384 2048

8 kHz100018.52837.0568 kHz24.704 3088

8 kHz100112.35224.7048 kHz24.704 3088

8 kHz101024.57649.1528 kHz16.384 2048

8 kHz101116.38432.7688 kHz16.384 2048

8 kHz110017.2834.568 kHz 17.28 2160

8 kHz1101 62.5 125 8 kHz 25 3125

Number

Name

Type

Pin Description

ICLK FS3 FS2 FS1 FS0 CLK/2 CLK 8k Crystal N

20 - 501110ICLK2*ICLKN/AICLK/23

10 - 251111ICLK/2ICLKN/AICLK 3

P1-P3 P4-P6 P7-P9 P10-P10

MK2049-45ASILFTR

Mfr. #:

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Manufacturer:

IDT

Description:

Clock Generators & Support Products 3.3 VOLT COMMUNICA. CLOCK VCXO PLL

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MK2049-45ASILFTR

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