Integer N PLL with Single Modulus Prescaler

Frequency synthesizer with single modulus prescaler based integer N PLL architecture

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Libraries:
Mixed-Signal Blockset / PLL / Architectures

Description

The Integer N PLL with Single Modulus Prescaler reference architecture uses a Single Modulus Prescaler block as the frequency divider in a PLL system. The frequency divider divides the frequency of the VCO output signal by an integer value to make it comparable to a PFD reference signal frequency.

Ports

Input

clk in — Input clock signal

scalar

Input clock signal, specified as a scalar. The signal at the clk in port is used as the reference signal for the PFD block in a PLL system.

Data Types: double

Output

clk out — Output clock signal

scalar

Output clock signal, specified as a scalar. The signal at the clk out port is the output of the VCO block in a PLL system.

Data Types: double

Parameters

Edit System — Break library block links and replace internal variables by appropriate values

button

Click to break the block links to the library. The internal variables are replaced by their values and the block becomes a simple subsystem.

Enable increased buffer size — Enable increased buffer size

button

Select to enable increased buffer size during the simulation. This increases the buffer size of all the building blocks in the PLL model that belong to the Mixed-Signal Blockset™/PLL/Building Blocks Simulink^® library. The building blocks are PFD, Charge Pump, Loop Filter, VCO, and Single Modulus Prescaler. By default, this option is deselected.

Buffer size for loop filter — Buffer size for loop filter

1000 (default) | positive integer scalar

Buffer size for the loop filter, specified as a positive integer scalar. This sets the number of extra buffer samples available during the simulation to the Convert Sample Time subsystem inside the loop filter.

Selecting different simulation solver or sampling strategies can change the number of input samples needed to produce an accurate output sample. Set the Buffer size for loop filter to a large enough value so that the input buffer contains all the input samples required.

Dependencies

This parameter is only available when the Enable increased buffer size option is selected.

Programmatic Use

• Use get_param(gcb,'NBufferFilter') to view the current value of Buffer size for loop filter.

• Use set_param(gcb,'NBufferFilter',value) to set Buffer size for loop filter to a specific value.

Buffer size for PFD, charge pump, VCO, prescaler — Buffer size for PFD, charge pump, VCO, and prescaler

10 (default) | positive integer scalar

Buffer size for the PFD, charge pump, VCO, and prescaler, specified as a positive integer scalar. This sets the buffer size of the PFD, Charge Pump, VCO, and Single Modulus Prescaler blocks inside the PLL model.

Selecting different simulation solver or sampling strategies can change the number of input samples needed to produce an accurate output sample. Set the Buffer size for PFD, charge pump, VCO, prescaler to a large enough value so that the input buffer contains all the input samples required.

Dependencies

This parameter is only available when the Enable increased buffer size option is selected.

Programmatic Use

• Use get_param(gcb,'NBuffer') to view the current value of Buffer size for PFD, charge pump, VCO, prescaler.

• Use set_param(gcb,'NBuffer',value) to set Buffer size for PFD, charge pump, VCO, prescaler to a specific value.

PFD

Configuration

Deadband compensation (s) — Delay added for active output near zero phase offset

30e-12 (default) | positive real scalar

Delay added for active output near zero phase offset, specified as a positive real scalar in seconds. Deadband is the phase offset band near zero phase offset for which the PFD output is negligible.

Programmatic Use

• Use get_param(gcb,'DeadbandCompensation') to view the current value of Deadband compensation (s).

• Use set_param(gcb,'DeadbandCompensation',value) to set Deadband compensation (s) to a specific value.

Data Types: double

Impairments

Enable impairments — Add circuit impairments to simulation

off (default) | on

Select to add circuit impairments such as rise/fall time and propagation delay to simulation. By default, this option is deselected.

Output step size calculation — Determine how output step size is calculated

Default (default) | Advanced

Determine how output step size is calculated:

• Select Default to calculate output step size from rise/fall time. Output step size (ΔT) is given by $$\Delta \text{T}=\frac{{\left(\text{Rise/fall time}\right)}^2}{6·\text{ 0}\text{.22}}$$.

• Select Advanced to calculate output step size from maximum frequency of interest. Output step size (ΔT) is given by $$\Delta \text{T}=\frac{\text{Rise/fall time}}{6·\text{ Maximum frequency of interest}}$$.

Dependencies

To enable this parameter, select Enable Impairments in the PFD tab.

Maximum frequency of interest (Hz) — Maximum frequency of interest at output

10e9 (default) | positive real scalar

Maximum frequency of interest at the output, specified as a positive real scalar in Hz.

Dependencies

To enable this parameter, select Enable Impairments in the PFD tab and choose Advanced for Output step size calculation.

Programmatic Use

• Use get_param(gcb,'MaxFreqInterest') to view the current value of Maximum frequency of interest (Hz).

• Use set_param(gcb,'MaxFreqInterest',value) to set Maximum frequency of interest (Hz) to a specific value.

Data Types: double

Rise/fall time (s) — 20% – 80% rise/fall time for up output port of PFD

30e-12 (default) | positive real scalar

20% – 80% rise/fall time for the up output port of the PFD, specified as a real positive scalar in seconds.

Dependencies

To enable this parameter, select Enable Impairments in the PFD tab.

Programmatic Use

• Use get_param(gcb,'RiseFallTime') to view the current value of Rise/fall time (s).

• Use set_param(gcb,'RiseFallTime',value) to set Rise/fall time (s) to a specific value.

Propagation Delay (s) — Delay from input port to output port of PFD

50e-12 (default) | positive real scalar

Delay from the input port to output port of the PFD, specified as a positive real scalar in seconds.

Dependencies

To enable this parameter, select Enable Impairments in the PFD tab.

Programmatic Use

• Use get_param(gcb,'PropDelay') to view the current value of Propagation Delay (s).

• Use set_param(gcb,'PropDelay',value) to set Propagation Delay (s) to a specific value.

Data Types: double

Charge pump

Configuration

Output current (A) — Design output current

1e-3 (default) | positive real scalar

Full scale magnitude of design output current, specified as a positive real scalar in amperes. This parameter is also reported as Charge pump current in the Loop Filter tab and is used to automatically calculate the filter component values of the loop filter. This parameter is tunable.

Programmatic Use

Block parameter: OutputCurrent

Type: character vector

Values: positive real scalar

Default: 1e-3

Data Types: double

Input threshold (V) — Logic switching threshold at input ports

0.5 (default) | real scalar

Logic switching threshold at input ports, specified as a real scalar in volts.

Programmatic Use

• Use get_param(gcb,'InputThreshold') to view the current value of Input threshold (V).

• Use set_param(gcb,'InputThreshold',value) to set Input threshold (V) to a specific value.

Data Types: double

Impairments

Enable current impairments — Add current impairments to simulation

off (default) | on

Select to add current impairments such as current imbalance and leakage current to simulation. By default, this option is deselected.

Current imbalance (A) — Difference between full scale positive and negative current

1e-7 (default) | positive real scalar

Difference between full scale positive and negative current, specified as a positive real scalar in amperes.

Dependencies

To enable this parameter, select Enable current impairments in the Charge pump tab.

Programmatic Use

• Use get_param(gcb,'CurrentImbalance') to view the current value of Current imbalance (A).

• Use set_param(gcb,'CurrentImbalance',value) to set Current imbalance (A) to a specific value.

Data Types: double

Leakage current (A) — Output current without any input

1e-8 (default) | nonnegative real scalar

Output current when both inputs are at logic zero, specified as a nonnegative real scalar in amperes.

Dependencies

To enable this parameter, select Enable current impairments in the Charge pump tab.

Programmatic Use

• Use get_param(gcb,'LeakageCurrent') to view the current value of Leakage current (A).

• Use set_param(gcb,'LeakageCurrent',value) to set Leakage current (A) to a specific value.

Data Types: double

Enable timing impairments — Add timing impairments to simulation

off (default) | on

Select to add timing impairments such as rise/fall time and propagation delay to simulation. By default, this option is deselected.

Output step size calculation — Determine how output step size is calculated

Default (default) | Advanced

Determine how output step size is calculated:

• Select Default to calculate output step size from rise/fall time. Output step size (ΔT) is given by $$\Delta \text{T}=\frac{{\left(\text{Rise/fall time}\right)}^2}{6·\text{ 0}\text{.22}}$$.

• Select Advanced to calculate output step size from maximum frequency of interest. Output step size (ΔT) is given by $$\Delta \text{T}=\frac{\text{Rise/fall time}}{6·\text{ Maximum frequency of interest}}$$.

Dependencies

To enable this parameter, select Enable timing impairments in the Charge Pump tab.

Maximum frequency of interest (Hz) — Maximum frequency of interest at output

10e9 (default) | positive real scalar

Maximum frequency of interest at the output, specified as a positive real scalar in Hz.

Dependencies

To enable this parameter, select Enable timing impairments in the Charge Pump tab and choose Advanced for Output step size calculation.

Programmatic Use

• Use get_param(gcb,'MaxFreqInterestCp') to view the current value of Maximum frequency of interest (Hz).

• Use set_param(gcb,'MaxFreqInterestCp',value) to set Maximum frequency of interest (Hz) to a specific value.

Data Types: double

Up

Rise/fall time (s) — 20% – 80% rise/fall time for up input port

5e-9 (default) | positive real scalar

20% – 80% rise/fall time for the up input port of the charge pump, specified as a positive real scalar in seconds.

Dependencies

To enable this parameter, select Enable timing impairments in the Charge pump tab.

Programmatic Use

• Use get_param(gcb,'RiseFallUp') to view the current value of Up Rise/fall time (s).

• Use set_param(gcb,'RiseFallUp',value) to set Up Rise/fall time (s) to a specific value.

Data Types: double

Propagation delay (s) — Total propagation delay from up input port to output port of charge pump

6e-9 (default) | positive real scalar

Total propagation delay from the up input port to output port of the charge pump, specified as a positive real scalar in seconds.

Dependencies

To enable this parameter, select Enable timing impairments in the Charge pump tab.

Programmatic Use

• Use get_param(gcb,'PropDelayUp') to view the current value of Up Propagation delay (s).

• Use set_param(gcb,'PropDelayUp',value) to set Up Propagation delay (s) to a specific value.

Data Types: double

Down

Rise/fall time — 20% – 80% rise/fall time for down input port

2e-9 (default) | scalar

20% – 80% rise/fall time for down input port of charge pump.

Dependencies

To enable this parameter, select Enable timing impairments in the Charge pump tab.

Programmatic Use

• Use get_param(gcb,'RiseFallDown') to view the current value of Down Rise/fall time (s).

• Use set_param(gcb,'RiseFallDown',value) to set Down Rise/fall time (s) to a specific value.

Data Types: double

Propagation delay (s) — Total propagation delay from up input port to output port of charge pump

4e-9 (default) | positive real scalar

Total propagation delay from the up input port to output port of the charge pump, specified as a positive real scalar in seconds.

Dependencies

To enable this parameter, select Enable timing impairments in the Charge pump tab.

Programmatic Use

• Use get_param(gcb,'PropDelayUp') to view the current value of Down Propagation delay (s).

• Use set_param(gcb,'PropDelayUp',value) to set Down Propagation delay (s) to a specific value.

Data Types: double

VCO

Specify using — Define how VCO output frequency is specified

Voltage sensitivity (default) | Output frequency vs. control voltage

Define how VCO output frequency is specified:

• Select Voltage sensitivity to specify output frequency from Voltage sensitivity (Hz/V) and Free running frequency (Hz).

• Select Output frequency vs. control voltage to interpolate output frequency from Control voltage (V) vector versus Output frequency (Hz) vector.

Programmatic Use

Block parameter: SpecifyUsing

Type: character vector

Values: Voltage sensitivity | Output frequency vs. control voltage

Default: Voltage sensitivity

Voltage sensitivity (Hz/V) — Measure of change in output frequency of VCO

100e6 (default) | positive real scalar

Measure of change in output frequency for input voltage change, specified as a positive real scalar with units in Hz/V. This parameter is also reported as VCO voltage sensitivity in the Loop Filter tab and is used to automatically calculate the filter component values of the loop filter.

Dependencies

To enable this parameter, select Voltage sensitivity in Specify using in the VCO tab.

Programmatic Use

Block parameter: Kvco

Type: character vector

Values: positive real scalar

Default: 100e6

Data Types: double

Free running frequency (Hz) — VCO output frequency without control voltage

1.8e9 (default) | positive real scalar

Frequency of the VCO without any control voltage input (0 V), or the quiescent frequency, specified as a positive real scalar in Hz.

Dependencies

To enable this parameter, select Voltage sensitivity in Specify using in the VCO tab.

Programmatic Use

Block parameter: Fo

Type: character vector

Values: positive real scalar

Default: 1.8e9

Data Types: double

Control voltage (V) — Control voltage values

[-5 0 5] (default) | real valued vector

Control voltage values of the VCO, specified as a real valued vector in volts.

Dependencies

To enable this parameter, select Output frequency vs. control voltage in Specify using in the VCO tab.

Programmatic Use

Block parameter: ControlVoltage

Type: character vector

Values: real valued vector

Default: [-5 0 5]

Data Types: double

Output frequency (Hz) — VCO output frequency values

[2e9 2.5e9 3e9] (default) | real valued vector

Output frequency of the values of the VCO, corresponding to the Control voltage (V) vector, specified in Hz.

Dependencies

To enable this parameter, select Output frequency vs. control voltage in Specify using in the VCO tab.

Programmatic Use

Block parameter: OutputFrequency

Type: character vector

Values: real valued vector

Default: [2e9 2.5e9 3e9]

Data Types: double

Output amplitude — Maximum amplitude of VCO output voltage

1 (default) | positive real scalar

Maximum amplitude of the VCO output voltage, specified as a positive real scalar.

Programmatic Use

Block parameter: Amplitude

Type: character vector

Values: positive real scalar

Default: 1

Data Types: double

Impairment

Add phase noise — Add phase noise as function of frequency

off (default) | on

Select to introduce phase noise as a function of frequency to the VCO. By default, this option is deselected.

Phase noise frequency offset (Hz) — Frequency offsets of phase noise from carrier frequency

[10e3 100e3 1e6 3e6 10e6] (default) | real valued vector

Frequency offsets of the phase noise from the carrier frequency, specified as a real valued vector in Hz.

Dependencies

To enable this parameter, select Add phase noise in the VCO tab.

Programmatic Use

Block parameter: Foffset

Type: character vector

Values: real valued vector

Default: [10e3 100e3 1e6 3e6 10e6]

Data Types: double

Phase noise level (dBc/Hz) — Phase noise power at specified frequency offsets relative to the carrier

[-77 -108 -134 -145 -154] (default) | real valued vector

Real valued vector specifying the phase noise power in a 1 Hz bandwidth centered at the specified frequency offsets relative to the carrier. The value is specified in dBc/Hz.

Dependencies

To enable this parameter, select Add phase noise in the VCO tab.

Programmatic Use

Block parameter: PhaseNoise

Type: character vector

Values: real valued vector

Default: [-77 -108 -134 -145 -154]

Data Types: double

Estimate phase noise parameters — Automatically estimate phase noise parameters

on (default) | off

Select to automatically estimate the phase noise parameters. By default, this option is selected.

You can deselect this option to define custom period jitter and flicker corner frequency.

Dependencies

To enable this parameter, select Add phase noise in the VCO tab.

Data Types: double

Period jitter (S) — Standard deviation of period jitter

2.6794e-15 (default) | positive real scalar

Standard deviation of the period jitter, specified as a positive real scalar in seconds. Period jitter is the deviation in cycle time of a clock signal with respect to the ideal period.

To enable this parameter, select Add phase noise and deselect Estimate phase noise parameters in the VCO tab.

Programmatic Use

Block parameter: PeriodJitter

Type: character vector

Values: positive real scalar

Default: 2.6794e-15

Data Types: double

Flicker corner frequency (Hz) — Corner frequency of flicker noise

517103.8168 (default) | scalar

Corner frequency of the flicker noise, specified as a scalar in hertz. Flicker corner frequency (Hz) is defined as the frequency at which the phase noise transitions from 1/f² to 1/f³ due to flicker noise. At this frequency, the spectral densities of period jitter and flicker noise are equal.

Dependencies

To enable this parameter, select Add phase noise and deselect Estimate phase noise parameters in the VCO tab.

Programmatic Use

Block parameter: CornerFrequency

Type: character vector

Values: scalar

Default: 517103.8168

Data Types: double

Plot fit — Plot specified and expected VCO output phase noise density

button

Click to plot the specified phase noise density and realizable expected output phase noise density of the VCO.

Prescaler

Clock divider value — Value by which the clock divider divides the input frequency

100 (default) | real positive scalar

Value by which the clock divider divides the input frequency, specified as a real positive scalar. This parameter is tunable.

Programmatic Use

• Use get_param(gcb,'N') to view the current value of Clock divider value.

• Use set_param(gcb,'N',value) to set Clock divider value to a specific value.

Data Types: double

Min clock divider value — Minimum value by which clock divider can divide input frequency

100 (default) | real positive scalar

Minimum value by which the clock divider can divide input frequency, specified as a real positive scalar. This parameter is also reported in the Loop Filter tab and is used to automatically calculate the filter component values of the loop filter.

Programmatic Use

• Use get_param(gcb,'Nmin') to view the current value of Min clock divider value.

• Use set_param(gcb,'Nmin',value) to set Min clock divider value to a specific value.

Data Types: double

Loop Filter

Filter component values — Determines how filter components are computed

Automatic (default) | Manual

Select how filter components for the loop filter are computed:

• Select Automatic to automatically compute filter components from system specifications. Resistance and capacitance edit boxes in the Loop Filter tab are not editable if this option is selected. Rather, the filter component values are calculated from Loop bandwidth (Hz), Phase margin (degrees), VCO voltage sensitivity, Charge pump current, and Min clock divider value. By default, this option is selected.

• Select Manual to manually enter the resistance and capacitance values to design a customized loop filter.

Loop bandwidth (Hz) — Frequency at which magnitude of open loop transfer function becomes 1

2e6 (default) | positive real scalar

Frequency at which the magnitude of the open loop transfer function becomes 1, specified as a positive real scalar in Hz. Lower values of Loop bandwidth (Hz) result in reduced phase noise and reference spurs at the expense of longer lock time and less phase margin.

Dependencies

This parameter is only available when Automatic is selected for the Filter Component values parameter in the Loop Filter tab.

Programmatic Use

• Use get_param(gcb,'Fc') to view the current value of Loop bandwidth (Hz).

• Use set_param(gcb,'Fc',value) to set Loop bandwidth (Hz) to a specific value.

Data Types: double

Phase margin (degrees) — Phase of open loop transfer function at loop bandwidth subtracted from 180°

45 (default) | positive real scalar

Phase of the open loop transfer function at the loop bandwidth subtracted from 180°, specified as a positive real scalar in degrees. For optimum lock time, select a phase margin between 40° and 55°.

Dependencies

This parameter is only available when Automatic is selected for the Filter Component values parameter in the Loop Filter tab.

Programmatic Use

• Use get_param(gcb,'Phi') to view the current value of Phase margin (degrees).

• Use set_param(gcb,'Phi',value) to set Phase margin (degrees) to a specific value.

Data Types: double

Loop filter type — Order of the loop filter

3rd Order Passive (default) | 2nd Order Passive | 4th Order Passive

Order of the loop filter. Applies a second-, third-, or fourth-order passive RC loop filter in the PLL system.

C1 (F) — Capacitance 1

1.31e-12 (default) | positive real scalar

Capacitor value C1, specified as a positive real scalar in farad.

Dependencies

This parameter is only editable when Manual is selected for the Filter Component values parameter in the Loop Filter tab.

Programmatic Use

• Use get_param(gcb,'C1') to view the current value of C1 (F).

• Use set_param(gcb,'C1',value) to set C1 (F) to a specific value.

Data Types: double

C2 (F) — Capacitance 2

1.44e-11 (default) | positive real scalar

Capacitor value C2, specified as a positive real scalar in farad.

Dependencies

This parameter is only editable when Manual is selected for the Filter Component values parameter in the Loop Filter tab.

Programmatic Use

• Use get_param(gcb,'C2') to view the current value of C2 (F).

• Use set_param(gcb,'C2',value) to set C2 (F) to a specific value.

Data Types: double

C3 (F) — Capacitance 3

9.41e-14 (default) | positive real scalar

Capacitor value C3, specified as a positive real scalar in farad.

Dependencies

• To enable this parameter, select 3rd Order Passive or 4th Order Passive in Loop filter type.

• This parameter is only editable when Manual is selected for the Filter Component values parameter in the Loop Filter tab.

Programmatic Use

• Use get_param(gcb,'C3') to view the current value of C3 (F).

• Use set_param(gcb,'C3',value) to set C3 (F) to a specific value.

Data Types: double

C4 (F) — Capacitance 4

331.5752 (default) | positive real scalar

Capacitor value C4, specified as a positive real scalar in farad.

Dependencies

• To enable this parameter, select 4th Order Passive in Loop filter type.

• This parameter is only editable when Manual is selected for the Filter Component values parameter in the Loop Filter tab.

Programmatic Use

• Use get_param(gcb,'C4') to view the current value of C4 (F).

• Use set_param(gcb,'C4',value) to set C4 (F) to a specific value.

Data Types: double

R2 (ohms) — Resistance 2

1.33e+04 (default) | positive real scalar

Resistor value R2, specified as a positive real scalar in ohms.

Dependencies

This parameter is only editable when Manual is selected for the Filter Component values parameter in the Loop Filter tab.

Programmatic Use

• Use get_param(gcb,'R2') to view the current value of R2 (ohms).

• Use set_param(gcb,'R2',value) to set R2 (ohms) to a specific value.

Data Types: double

R3 (ohms) — Resistance 3

1.7e+05 (default) | positive real scalar

Resistor value R3, specified as a positive real scalar in ohms.

Dependencies

• To enable this parameter, select 3rd Order Passive or 4th Order Passive in Loop filter type.

• This parameter is only editable when Manual is selected for the Filter Component values parameter in the Loop Filter tab.

Programmatic Use

• Use get_param(gcb,'R3') to view the current value of R3 (ohms).

• Use set_param(gcb,'R3',value) to set R3 (ohms) to a specific value.

Data Types: double

R4 (ohms) — Resistance 4

28.1695 (default) | positive real scalar

Resistor value R4, specified as a positive real scalar in ohms.

Dependencies

• To enable this parameter, select 4th Order Passive in Loop filter type.

• This parameter is only editable when Manual is selected for the Filter Component values parameter in the Loop Filter tab.

Programmatic Use

• Use get_param(gcb,'R4') to view the current value of R4 (ohms).

• Use set_param(gcb,'R4',value) to set R4 (ohms) to a specific value.

Data Types: double

Enable impairments — Add circuit impairments to simulation

off (default) | on

Select to add circuit impairments such as operating temperature to determine thermal noise to simulation. By default, this option is deselected.

Operating temperature (℃) — Temperature to determine the level of thermal noise

30 (default) | real scalar

Temperature of the resistor, specified as a real scalar in ℃. Operating temperature determines the level of thermal (Johnson) noise.

Dependencies

To enable this parameter, select Enable impairments in the Loop Filter tab.

Programmatic Use

• Use get_param(gcb,'Temperature') to view the current value of Operating temperature.

• Use set_param(gcb,'Temperature',value) to set Operating temperature to a specific value.

Data Types: double

Export Loop Filter Component Values — Export loop filter component values

button

Click to export loop filter component values to a spreadsheet (XLS file) or as comma-separated values (CSV file).

Probe

PFD up and PFD down (pfd_up and pfd_down) — Select to probe PFD outputs

off (default) | on

Select to probe the PFD output wires (pfd_up and pfd_down) to view the response of the PFD.

Charge pump output (cp_out) — Select to probe charge pump output

off (default) | on

Select to probe the charge pump output wire (cp_out) to view the response of the Charge Pump.

Loop filter output (lf_out) — Select to probe loop filter output

off (default) | on

Select to probe loop filter output wire (lf_out) to view the response of the Loop Filter. The loop filter output provides the control voltage to the VCO.

Prescaler output (ps_out) — Select to probe prescaler output

off (default) | on

Select to probe the prescaler output wire (ps_out) to view the response of the Fractional Clock Divider with Accumulator.

Analysis

Open Loop Analysis — Plot the presimulation open loop analysis

on (default) | off

Select to plot the gain margin and phase margin of the PLL system before simulation. By default, this option is selected.

Closed Loop Analysis — Plot the presimulation closed loop analysis

off (default) | on

Select to plot the pole-zero map, loop bandwidth, step response, and impulse response of the PLL system before simulation. You must have a license to Control System Toolbox™ to plot the step response and impulse response of the PLL system. By default, this option is deselected.

Plot Loop Dynamics — Plot loop dynamics of PLL system

button

Click to plot the presimulation loop dynamics of the PLL system.

Estimate phase noise — Estimate phase noise from input clock

off (default) | on

Select to estimate the phase noise from the input clock. By default, this option is deselected.

Reference frequency (Hz) — Reference frequency of input clock

10e6 (default) | positive real scalar

Reference frequency of input clock, specified as a positive real scalar.

Dependencies

To enable this parameter, select Estimate Phase Noise in the Analysis tab.

Programmatic Use

Block parameter: RefFreq

Type: character vector

Values: positive real scalar

Default: 10e6

Resolution bandwidth (Hz) — Smallest positive frequency that can be resolved

10e3 (default) | positive real scalar

Smallest positive frequency that can be resolved, specified as a real positive scalar. The Resolution bandwidth (Hz) is used to determine window length for spectral analysis using the Welch method. For more information, see Welch's Method of Averaged Modified Periodograms.

In general, Resolution bandwidth (Hz) should be less than the lowest offset frequency value.

Dependencies

To enable this parameter, select Estimate Phase Noise in the Analysis tab.

Programmatic Use

Block parameter: Rbw

Type: character vector

Values: positive real scalar

Default: 10e3

Frequency offset vector (Hz) — Frequency points relative to fundamental frequency where phase noise is calculated

[10e3 100e3 1e6 3e6 10e6] (default) | real valued vector

Frequency points relative to fundamental frequency where phase noise is calculated, specified as a real valued vector in Hz.

Dependencies

To enable this parameter, select Estimate Phase Noise in the Analysis tab.

Programmatic Use

Block parameter: FrOffset

Type: character vector

Values: real valued vector

Default: [10e3 100e3 1e6 3e6 10e6]

Target phase-noise levels (dBc/Hz) — Target phase noise profile for given frequency offset vector

-inf (default) | vector | scalar

Target phase noise profile for given frequency offset vector, specified in dBc/Hz. Target phase noise levels (dBc/Hz) is the phase noise power in a 1 Hz bandwidth centered at the specified frequency offsets relative to the carrier.

Dependencies

To enable this parameter, select Estimate Phase Noise in the Analysis tab.

Programmatic Use

Block parameter: TargetPn

Type: character vector

Values: vector | scalar

Default: -inf

Plot estimated phase noise — Plot estimated input clock phase noise

button

Click to plot the estimated input clock phase noise.

Version History

Introduced in R2019a

R2023b: Estimate VCO Phase Noise Parameters

You can either estimate the phase noise parameters of the VCO, or manually define the custom period jitter and flicker corner frequency. You can also plot the specified and expected output phase noise density of the VCO.