CX72302-11 - Conexant Systems, Inc.

CX72300/1/2

Phase Noise

Application Note

101348A

February 2001

101348A Conexant

Information in this document is provided in connection with Conexant Systems, Inc. (“Conexant”) products. These materials are

provided by Conexant as a service to its customers and may be used for informational purposes only. Conexant assumes no

responsibility for errors or omissions in these materials. Conexant may make changes to specifications and product descriptions at

any time, without notice. Conexant makes no commitment to update the information and shall have no responsibility whatsoever for

conflicts or incompatibilities arising from future changes to its specifications and product descriptions.

No license, express or implied, by estoppel or otherwise, to any intellectual property rights is granted by this document. Except as

provided in Conexant’s Terms and Conditions of Sale for such products, Conexant assumes no liability whatsoever.

THESE MATERIALS ARE PROVIDED “AS IS” WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESS OR IMPLIED, RELATING

TO SALE AND/OR USE OF CONEXANT PRODUCTS INCLUDING LIABILITY OR WARRANTIES RELATING TO FITNESS FOR A

PARTICULAR PURPOSE, CONSEQUENTIAL OR INCIDENTAL DAMAGES, MERCHANTABILITY, OR INFRINGEMENT OF ANY

PATENT, COPYRIGHT OR OTHER INTELLECTUAL PROPERTY RIGHT. CONEXANT FURTHER DOES NOT WARRANT THE

ACCURACY OR COMPLETENESS OF THE INFORMATION, TEXT, GRAPHICS OR OTHER ITEMS CONTAINED WITHIN THESE

MATERIALS. CONEXANT SHALL NOT BE LIABLE FOR ANY SPECIAL, INDIRECT, INCIDENTAL, OR CONSEQUENTIAL

DAMAGES, INCLUDING WITHOUT LIMITATION, LOST REVENUES OR LOST PROFITS, WHICH MAY RESULT FROM THE USE

OF THESE MATERIALS.

Conexant products are not intended for use in medical, lifesaving or life sustaining applications. Conexant customers using or selling

Conexant products for use in such applications do so at their own risk and agree to fully indemnify Conexant for any damages

resulting from such improper use or sale.

The following are trademarks of Conexant Systems, Inc.: Conexant™, the Conexant C symbol, and “What’s Next in Communications

Technologies”™. Product names or services listed in this publication are for identification purposes only, and may be trademarks of

third parties. Third-party brands and names are the property of their respective owners.

For additional disclaimer information, please consult Conexant’s Legal Information posted at www.conexant.com,whichis

incorporated by reference.

Reader Response: Conexant strives to produce quality documentation and welcomes your feedback. Please send comments and

suggestions to tech.pubs@conexant.com. For technical questions, contact your local Conexant sales office or field applications

engineer.

101348A Conexant iii

Table of Contents

List of Figures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . v

Phase Noise . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Phase Noise Contributors in a PLL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Step Size . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Crystal Oscillator Phase Noise . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

CX7230x Synthesizer Phase Noise . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Phase/Frequency Detector and Divider Noise Floors . . . . . . . . . . . . . . . . . . . . . 5

Delta-Sigma Quantization Noise. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

VCO Phase Noise . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Loop Bandwidth . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Effects of Larger Loop Bandwidths . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Table of Contents CX72300/1/2

Phase Noise

iv Conexant 101348A

CX72300/1/2 List of Figures

Phase Noise

101348A Conexant v

List of Figures

Figure 1. PLL Synthesizer Loop . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Figure 2. Typical Delta-Sigma Quantization Noise . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Figure 3. Typical VCO Free Running Phase Noise. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Figure 4. Measured Total Phase Noise Performance of CX72300 Main Synthesizer. . . . . . . . . . . . . . 11

List of Figures CX72300/1/2

Phase Noise

vi Conexant 101348A

101348A Conexant 1

Phase Noise

This Application Note describes the total output phase noise performance of a PLL when using the

Conexant CX7230x family of synthesizer ICs.

Phase Noise Contributors in a PLL

In any oscillator, the intention is to generate a single tone sinewave that has constant amplitude and

frequency. In a real application, assuming the amplitude is constant, there would appear random

spectral components caused by thermal noise, 1/f noise of transistors and the finite Q of a resonant

circuit. These random spectral components can be collectively viewed on a spectrum analyzer as

phase noise.

The total output phase noise of a PLL is determined by three factors:

1. crystal oscillator phase noise,

2. synthesizer phase noise, and

3. VCO phase noise.

Step Size

The Conexant CX7230x family of synthesizers achieve their step size by using a ∆Σ fractional-N

modulator. As a result of this, there are some differences in calculating total phase noise compared

to the techniques applied to integer-N synthesizers. This will be closely examined in order to fully

appreciate the impact that step size has on the total phase noise of a PLL.

The Conexant CX72301 and CX72300 synthesizers features 18-bit fractionality on the main

synthesizer portion, which gives a resolution of 262,144 steps with respect to the internal reference

frequency. The CX72302 features a 16-bit resolution. These step sizes are related to the internal

reference and not to the output frequency, which means that there will be the same step size in the

1.0 GHz version or the 2.1 GHz version PLL.

The formula for computing the step size is:

[1]

where:

[2]

Step size [Hz] FXtal R⁄

218

-------------------=

Xtal Fref

⁄=

Phase Noise CX72300/1/2

Phase Noise Contributors in a PLL Phase Noise

2Conexant 101348A

Example 1: Using a 20 MHz crystal and a reference division of R = 1 yields,

This represents the minimum step size achievable with a 20 MHz crystal oscillator and R=1.

Example 2: Using a 20 MHz crystal and a reference division of R = 32 yields,

This represents the minimum step size achievable with a 20 MHz crystal oscillator and R=32.

The 2.38 Hz and 76.29 Hz step sizes represent the minimum and maximum values when using

a 20 MHz crystal and 18-bit resolution. The difference is due to selecting a different value of R

which sets the internal reference frequency.

In an integer-N synthesizer, the crystal reference is divided by an integer number to achieve an

internal frequency which is equal to the step size.

In these conventional dual modulus loops, the step size is a result of the VCO being divided

down in frequency by a prescaler that only produces integer divisions.

The net result is that the step size is equal to the reference frequency at the phase detector.

Therefore, the divide ratio can be integers such as 46, 47, 48, etc.

In a ∆Σ-based synthesizer, the prescaler is modulated in a statistical fashion to realize division

ratios that are not restricted to integers.

An 18-bit ∆Σ fractional-N synthesizer can make the resolution 262144 finer in step size. In

other words, there are 262144 steps between 46 and 47 and so on.

Let us look at the differences in generating the step size in an integer-N and fractional-N and

what they mean to the resultant value of N in a PLL.

Example 3: Calculate the value of N in a 900 MHz integer-N PLL to generate a 6.25 kHz step

size using a 20 MHz crystal.

Step size in an integer-N PLL is determined by:

[3]

This means that the crystal frequency has been divided by 3200 to achieve a step size of

6.25 kHz.

In an integer-N PLL, step size is also equal to the internal reference frequency. Therefore, the

internal reference frequency is also 6.25 kHz.

Step size 20 MHz 1⁄

262,144

--------------------------=

Step size 76.29 Hz=

Step size 20 MHz 32⁄

262,144

-----------------------------=

Step size 2.38 Hz=

Step size FXtal

-----------=

6.25 kHz 20 MHz

-------------------=

R3200=

CX72300/1/2 Phase Noise

Phase Noise Phase Noise Contributors in a PLL

101348A Conexant 3

To calculate N, apply the following equation:

[4]

Therefore, an integer-N synthesizer PLL with an output of 900 MHz and a step size of 6.25 kHz

has N equal to 144,000.

Example 4: Calculate the value of N in a 900 MHz PLL using the CX72301 fractional-N

synthesizer to generate a 6.25 kHz step size using a 20 MHz crystal.

Using the formula [3] for calculating step size in a fractional-N and making R = 1,

As we can see the resultant step size is 76 Hz which exceeds the 6.25 kHz specification by 82

times.

To calculate N, use the following equation:

R = 1 means that Fref is equal to FXtal therefore,

Therefore, using the CX72301 fractional-N synthesizer to generate a 900 MHz output with a

76 Hz step size means that N is 45.

As a result, the integer-N PLL needed a large N value of 144,000 to achieve the required

6.25 kHz step size, where the 18-bit fractional-N PLL only needed N to be 45 while achieving a

76 Hz step size.

When using the Conexant synthesizers in fractional-N mode, it is recommended that a crystal

reference frequency of less than 25 MHz be divided down only to achieve extremely fine resolution

(see Delta Sigma Quantization Noise and Synthesizer Phase Noise below). This will ensure a

superior performance with respect to phase noise.

Reference division is required when a crystal frequency between 25 and 50 MHz is used, in

which case this crystal frequency must be divided down to 25 MHz or less by choosing a value of

R = 2. This ensures that the final value of the internal reference frequency is below the maximum of

25 MHz.

NFout

Fref

---------=

N900 MHz

6.25 kHz

----------------------=

N 144,000=

Step size 20 MHz 1⁄

262,144

--------------------------=

N900 MHz

20 MHz

----------------------=

N45=

Phase Noise CX72300/1/2

Phase Noise Contributors in a PLL Phase Noise

4Conexant 101348A

Crystal Oscillator Phase Noise

The dominant close-in phase noise contributor to the total phase noise is the crystal oscillator phase

noise multiplied by the division ratio N divided by the internal reference divider. The N/R term

relates the internal reference back to the crystal frequency.

[5]

where:

Example 5: Calculate the added phase noise to a 20 MHz crystal in a PLL operating at

920 MHz with R = 1. As R = 1 the formula reduces to 20 log (N).

Therefore, the additional phase noise contribution of 33 dB is added to the original phase noise

of the crystal.

Example 6: Using the 33 dB additional phase noise, calculate the resultant phase noise of the

crystal at a 10 kHz offset where the original crystal oscillator phase noise was –130 dBc/Hz at the

10 kHz offset.

Therefore, measured at 10 kHz offset from the carrier, the multiplied phase noise contribution

of a 20 MHz crystal that has a –130 dBc/Hz phase noise brings the total phase noise of a 920 MHz

synthesizer PLL to –97 dBc/Hz.

The previous calculations were performed using an external crystal oscillator. The Conexant

CX7230x synthesizers have an integrated internal crystal oscillator that operates at up to 50 MHz

and has a phase noise floor of –130 dBc/Hz. The internal reference frequency Fref, has a maximum

frequency of 25 MHz.

Crystal phase noise contributions are typically greater in PLL systems with small step size

employing integer-N synthesizers. In this case, the internal reference of the synthesizer will be

divided down significantly to achieve a very fine step size.

Figure 1. PLL Synthesizer Loop

/ R ∅

/ N

FXtal Fref VCO

Tune

Fout

∆Σ

101348_001

20 log (N/R)

NFout

Fref

---------=

Added Phase Noise 20 920 MHz

20 MHz

----------------------

èø

æö

log=

Added Phase Noise 33 dB=

130 dBc–Hz33dB+⁄97 dBc–Hz⁄=

CX72300/1/2 Phase Noise

Phase Noise Phase Noise Contributors in a PLL

101348A Conexant 5

As we saw earlier, when the crystal frequency is multiplied up, the phase noise increases by

20 log (N). However, when the crystal frequency is divided down as occurs when R is greater than

1, the divided down internal reference frequency Fref also has the phase noise decreased at the same

rate of 20 log (N). This means that if Fref has been divided down from FXtal, the phase noise seen at

Fref will have a better phase noise than that of the original crystal.

Example 7: Calculate the crystal phase noise contribution at the VCO output to the total phase

noise of a PLL when N has a value of 144,000 as in Example 3, R = 1 and a phase detector noise

floor of –150 dBc / Hz.

The resultant value of –46 dBc/Hz would make a very noisy PLL design.

CX7230x Synthesizer Phase Noise

The three sources of phase noise in a delta-sigma fractional-N synthesizer are the:

1. divider noise floor

2. multiplied phase/frequency detector noise floor, and

3. quantization noise of the delta-sigma modulator.

The divider phase noise and the multiplied phase/frequency detector noise floor normally

contribute phase noise inside the loop bandwidth. The quantization noise normally occurs around

1-10 MHz offset from the carrier.

Phase/Frequency Detector and Divider Noise Floors

The CX7230x Fractional-N Synthesizer family possesses internal VCO divider circuits. As such, it

is difficult to discern the divider noise from the phase/detector noise floor. This being the case, we

will refer to the combined divider and phase/frequency detector noise floor as simply the

phase/frequency detector noise floor (–135 dBc/Hz for the CX7230x series). This occurs at Point A

in Figure 1 of the PLL synthesizer diagram.

As in the case of the crystal phase noise example, systems employing integer-N require the

internal reference frequency to be very low in order to achieve the required step size. This causes the

multiplied phase detector noise to rise inside the loop bandwidth. In this case, the noise floor is set

by the noise floor of the phase/frequency detector plus the 20 log (N) factor.

Example 8: Calculate the phase noise contribution of an integer-N synthesizer used to generate

a 920 MHz output with a step size of 30 kHz.

The internal reference frequency is 30 kHz. We can now calculate the phase noise using

20 log (N).

Where N is:

Therefore,

VCO Output Phase Noise due to Crystal Oscillator Phase Noise 150 dBc Hz 20 log 144,000()+⁄–=

VCO Output Phase Noise due to Crystal Oscillator Phase Noise 46 dBc Hz⁄–=

NFout

Fref

---------=

0log 920 MHz

30 kHz

----------------------

èø

æö

89.7 dB=

Phase Noise CX72300/1/2

Phase Noise Contributors in a PLL Phase Noise

6Conexant 101348A

The value of N is 3833. The 89.7 dB result is now added to the phase/frequency detector noise

floor.

If the phase/frequency detector noise floor of the synthesizer is –150 dBc/Hz at an internal

reference frequency of 30 kHz, the resultant value would be:

The result of –60 dBc/Hz would be the phase/frequency detector noise contribution inside the

loop bandwidth to the total phase noise of the PLL. To determine the total output phase noise, the

multiplied noise contribution of the crystal oscillator must be added to this value.

Example 9: Calculate the phase noise contribution of the Conexant CX72301 fractional-N

synthesizer used to generate a 920 MHz output with a step size of 30 kHz.

As the CX72301 uses fractional-N to achieve step size, the internal reference is not a small

multiple of the required step size. The internal reference is determined by the crystal reference

frequency divided by R (see Crystal Oscillator Phase Noise). Therefore, we need to know the crystal

reference frequency and the value of the reference divider R. Assume a 20 MHz crystal and R = 1.

With the reference divider R = 1, the internal reference frequency is equal to the crystal reference

frequency of 20 MHz.

Now calculate 20 log (N) where:

The value of N is 46. The 33 dB result is now added to both the phase/frequency detector noise

floor and the crystal oscillator noise floor.

The phase/frequency detector noise floor of the CX72301 synthesizer is –135 dBc/Hz, while

the crystal oscillator noise floor is –130 dB/Hz, therefore:

The –102 dBc/Hz contribution of the phase/frequency detector must be added to the

–97 dBc/Hz noise contribution of the crystal oscillator, yielding an output phase noise at the VCO

of –95.8 dB/Hz measured inside the loop bandwidth (keep in mind that if the reference divider was

set to R = 2, then the crystal reference noise floor at the phase detector input would then be 6 dB

better, or –135 dBc/Hz.

This offers a significant improvement over the phase noise performance that an integer-N

solution could provide (compare with Example 8). What is more, the CX72301 Fractional-N

solution offers a step size of 76 Hz as an added benefit.

150 dBc–Hz89.7dBc+⁄60 dBc–Hz⁄=

NFout

Fref

---------=

20 log 920 MHz

20 MHz

----------------------

èø

æö

33 dB=

135 dBc–Hz33dB+⁄102 dBc– Hz phase detector noise contribution⁄=

130 dBc–Hz33dB+⁄97 dBc Hz crystal oscillator noise contribution⁄–=

CX72300/1/2 Phase Noise

Phase Noise Phase Noise Contributors in a PLL

101348A Conexant 7

Delta-Sigma Quantization Noise

Because the Conexant synthesizers use a ∆Σ modulator to achieve the fractionality, the designer

must be aware of the far-out quantization noise. This quantization noise occurs at point B in

Figure 1 of the PLL synthesizer diagram. The quantization noise is only added to the feedback loop

and not to the VCO noise; as a result, the quantization noise is attenuated by the loop filter.

The clock frequency of the ∆Σ modulator is set by the internal reference frequency.

where:

[6]

The formula is:

[7]

Example 10: Calculate the clock frequency of the ∆Σ modulator if the crystal frequency is 50

MHz crystal and R = 2,

This yields a 25 MHz ∆Σ modulator clock frequency.

Two factors are related to the internal reference that effect quantization noise.

The first is, as the internal reference frequency increases, the amplitude of the quantization

noise decreases. Increasing the internal reference frequency by a factor of 10, decreases the

quantization noise by approximately 70 dB.

The second is, as the internal reference frequency increases, the frequency at which the

quantization noise will occur increases proportionally as well. Increasing the internal reference

frequency by a factor of 10, increases the frequency of the quantization noise by 10.

These are two additional reasons for keeping the internal reference frequency high. Having a

low internal reference frequency would significantly raise the quantization noise and also move it

inside the loop bandwidth where the loop filter could not attenuate it.

Figure 2. Typical Delta-Sigma Quantization Noise

FModulator Fref

FModulator

FXtal

------------=

FModulator

50 MHz

-------------------=

SSB Phase Noise (dBc/Hz)

Frequency (Hz)

1 x 1041 x 1051 x 1061 x 1071 x 108

101348_003

–20

–40

–60

–80

–100

–120

–140

–160

Phase Noise CX72300/1/2

Phase Noise Contributors in a PLL Phase Noise

8Conexant 101348A

VCO Phase Noise

The free running phase noise of the VCO is typically the dominant contribution to the total phase

noise outside the loop bandwidth and sets the far-out phase noise of the PLL. This occurs at point C

in Figure 1.

Inside the loop bandwidth the VCO phase noise is attenuated by the loop filter. As the loop

bandwidth increases the VCO phase noise contribution inside the loop decreases.

In a single loop PLL architecture, the VCO free running phase noise cannot be corrected

outside the loop filter bandwidth. As a result, it is essential that VCO free running phase noise from

about 100 kHz to 10 MHz be below the required system phase noise mask, or to correct for the VCO

phase noise the loop filter bandwidth would have to be extremely large.

In a fractional-N synthesizer the loop bandwidth can be much larger than in traditional

synthesizers, however making the bandwidth too large would be impractical as the crystal oscillator

phase noise, synthesizer phase noise and quantization noise contributions would be affected.

Typical VCO free running phase noise is –150 to –140 dBc/Hz at a 10 MHz frequency offset

and –120 to –110 dBc/Hz at a 100 kHz frequency offset.

In selecting a VCO with poor phase noise, the designer may be faced with trading off the VCO

phase noise inside the loop against the crystal oscillator and synthesizer phase noise.

Figure 3. Typical VCO Free Running Phase Noise

SSB Phase Noise (dBc/Hz)

Frequency (Hz)

1 x 1031 x 1041 x 1051 x 1061 x 1071 x 108

101348_004

–40

–60

–80

–100

–120

–140

–160

CX72300/1/2 Phase Noise

Phase Noise Phase Noise Contributors in a PLL

101348A Conexant 9

Loop Bandwidth

Loop bandwidth in this document refers to the unity gain open loop bandwidth.

Larger loop bandwidths can be achieved with Conexant CX7230x ICs over traditional

synthesizers due to the following four reasons:

1. Higher Internal Reference Frequency

PLL synthesizer loop bandwidth is normally limited to 1/10 the internal reference

frequency.

As the CX7230x series can have an internal reference frequency as high as 25 MHz while

maintaining very fine step size, this is not a limiting factor.

2. Crystal Oscillator Phase Noise

The relatively small value of 20 log (N) which is added to the crystal oscillator phase noise

reduces the PLL close-in phase noise.

3. Phase/Frequency Detector Noise Floor

The multiplied noise floor of the phase/frequency detector is below that of traditional

synthesizers because the value of N is relatively small. This reduces the resultant

synthesizer phase noise contribution inside the loop bandwidth.

Effects of Larger Loop Bandwidths

Increasing the loop bandwidth frequency has both positive and negative effects on the overall PLL

performance as indicated below.

Switching Time

The switching time of the PLL decreases as the loop bandwidth increases. To improve acquisition

time the loop bandwidth should be increased.

The speed is approximated using:

[8]

Example 11: Using a 35 kHz loop bandwidth,

which yields approximately 143 µs switching time.

VCO Phase Noise

The VCO phase noise is improved by the loop filter only inside the loop bandwidth. Therefore, as

the loop bandwidth is widened, the attenuation of the loop filter on the close-in VCO phase noise is

improved. To improve the close-in VCO phase noise the loop bandwidth frequency should be

increased.

Delta-Sigma Quantization Noise

The loop filter attenuates the quantization noise which typically occurs around 1–10 MHz.

Therefore, as the loop bandwidth increases, so does the quantization noise. To improve the

quantization noise the loop bandwidth frequency should be decreased.

Switching Time 5

Loop Bandwidth

----------------------------------------≈

Switching Time 5

35 kHz

-----------------

≈

Phase Noise CX72300/1/2

Phase Noise Contributors in a PLL Phase Noise

10 Conexant 101348A

Crystal Oscillator Phase Noise

The loop filter attenuates the crystal oscillator phase noise outside the loop. Therefore, as the loop

bandwidth is increased, the point where the filter roll-off starts to attenuate the crystal oscillator

phase noise is moved higher in frequency as well. To improve the crystal oscillator phase noise, the

loop bandwidth frequency should be decreased.

Synthesizer Phase Noise

The loop filter attenuates the synthesizer phase noise outside the loop bandwidth frequency.

Therefore, as the loop bandwidth is increased, the point where the filter roll-off starts to attenuate

the synthesizer phase noise gets moved higher in frequency as well. To improve the synthesizer

phase noise the loop bandwidth frequency should be decreased.

Microphonics

Larger loop bandwidths help the PLL recover quickly from the effects of microphonics. The crystal

oscillator is a piezoelectric device, which means that it is susceptible to short term phenomenon

such as shock, vibration, and thermal earthquakes. Thermal earthquakes are caused by the

mismatching of the coefficients of thermal expansion in the materials. This mismatch causes a

buildup of stress that is periodically relieved by a sudden shift in mechanical alignment, thus

inducing a mechanical shock.

Load Pulling of the VCO

With a larger loop bandwidth, the VCO will be less susceptible to any variations in the load. As a

result, the synthesizer can correct the VCO more quickly.

Otherwise, in a narrow loop, it is the reverse isolation of the VCO that is critical to protecting

against load pull.

CX72300/1/2 Phase Noise

Phase Noise Phase Noise Contributors in a PLL

101348A Conexant 11

In Figure 4, we can see the measured phase noise performance of the CX72300 PLL

synthesizer. A typical performance crystal oscillator and VCO were used in this example.

The loop filter has been optimized to 80 kHz to minimize the effect of the crystal, VCO and

quantization noise.

Figure 4. Measured Total Phase Noise Performance of CX72300 Main Synthesizer

101348_005

10 dB/

RL –50 dBc/Hz 10.0 kHz

–94.17 dBc/Hz

100 Hz Frequency Offset

From 1.200 GHz Carrier

SSB Phase Noise (dBc/Hz)

10 MHz

SPOT FRQ =

Crystal Oscillator Frequency 24 MHz

Internal Reference Frequency 12 MHz

PLL Output Frequency 1200 MHz

Loop Filter Bandwidth 80 kHz

Step Size 46 Hz

Phase Noise CX72300/1/2

Phase Noise Contributors in a PLL Phase Noise

12 Conexant 101348A

Further Information

literature@conexant.com

(800) 854-8099 (North America)

(949) 483-6996 (International)

Printed in USA

World Headquarters

Conexant Systems, Inc.

4311 Jamboree Road

Newport Beach, CA

92660-3007

Phone: (949) 483-4600

Fax 1: (949) 483-4078

Fax 2: (949) 483-4391

Americas

U.S. Northwest/

Pacific Northwest – Santa Clara

Phone: (408) 249-9696

Fax: (408) 249-7113

U.S. Southwest – Los Angeles

Phone: (805) 376-0559

Fax: (805) 376-8180

U.S. Southwest – Orange County

Phone: (949) 483-9119

Fax: (949) 483-9090

U.S. Southwest – San Diego

Phone: (858) 713-3374

Fax: (858) 713-4001

U.S. North Central – Illinois

Phone: (630) 773-3454

Fax: (630) 773-3907

U.S. South Central – Texas

Phone: (972) 733-0723

Fax: (972) 407-0639

U.S. Northeast – Massachusetts

Phone: (978) 367-3200

Fax: (978) 256-6868

U.S. Southeast – North Carolina

Phone: (919) 858-9110

Fax: (919) 858-8669

U.S. Southeast – Florida/

South America

Phone: (727) 799-8406

Fax: (727) 799-8306

U.S. Mid-Atlantic – Pennsylvania

Phone: (215) 244-6784

Fax: (215) 244-9292

Canada – Ontario

Phone: (613) 271-2358

Fax: (613) 271-2359

Europe

Europe Central – Germany

Phone: +49 89 829-1320

Fax: +49 89 834-2734

Europe North – England

Phone: +44 1344 486444

Fax: +44 1344 486555

Europe – Israel/Greece

Phone: +972 9 9524000

Fax: +972 9 9573732

Europe South – France

Phone: +33 1 41 44 36 51

Fax: +33141443690

Europe Mediterranean – Italy

Phone: +39 02 93179911

Fax: +39 02 93179913

Europe – Sweden

Phone: +46 (0) 8 5091 4319

Fax: +46 (0) 8 590 041 10

Europe – Finland

Phone: +358 (0) 9 85 666 435

Fax: +358 (0) 9 85 666 220

Asia – Pacific

Taiwan

Phone: (886-2) 2-720-0282

Fax: (886-2) 2-757-6760

Australia

Phone: (61-2) 9869 4088

Fax: (61-2) 9869 4077

China–Central

Phone: 86-21-6361-2515

Fax: 86-21-6361-2516

China–South

Phone: (852) 2 827-0181

Fax: (852) 2 827-6488

China – South (Satellite)

Phone: (86) 755-518-2495

China–North

Phone: (86-10) 8529-9777

Fax: (86-10) 8529-9778

India

Phone: (91-11) 692-4789

Fax: (91-11) 692-4712

Korea

Phone: (82-2) 565-2880

Fax: (82-2) 565-1440

Korea (Satellite)

Phone: (82-53) 745-2880

Fax: (82-53) 745-1440

Singapore

Phone: (65) 737 7355

Fax: (65) 737 9077

Japan

Phone: (81-3) 5371 1520

Fax: (81-3) 5371 1501

www.conexant.com

Offi

ces