Phase Noise to Jitter Calculator

Frequently Asked Questions

Often FPGA or SoC vendors will specify the reference clock requirements in terms of phase noise, so designers can use this Phase Noise to Jitter Calculator tool to determine the jitter requirements, which can be used to find timing ICs more readily. The tool will estimate the phase jitter, period jitter and cycle-to-cycle jitter for the data given.
Note: The calculation tool is provided as a guideline only. The utility is not meant to be exhaustive nor provide calculations for every possible scenario.
 
 

1 — Specify Application Data or Load Examples

Select Application and Example Data

Select the initial application by choosing from the drop-down list. Once you have chosen an application, a link will appear that will allow you to load pre-set values that would be typical for that application. Click that link to load the pre-set values. You may edit the pre-set values or enter your own. Enter the frequency measurement (in MHz) applicable to the phase noise and spurious data.

Select Integration Bandwidth

Specify the jitter integration bandwidth applicable for the application and data. This control is used to provide a phase jitter value and can be left default for applications that care about period or cycle-to-cycle jitter. Specify the filter type required for the application.
 
 

2 — Phase Noise Data Pairs

Specify the number of phase noise data pairs and enter the phase noise data in each field. You can accept the defaults from the pre-set application example or enter your own data.
To add or delete data pairs, choose the correct number of pairs from the drop-down menu.
 
 

3 — Spurious (optional)

Entering spurious data is optional. You can accept the default values from the example or enter your own data. Specify the number of spurious and the frequency (Hz) and amplitude (dBc).
To add or delete spurious data pairs, choose the correct number of pairs from the drop-down menu.
 
 

Reset Inputs

To reset all inputs back to the starting state, click/tap the Reset Inputs button.
 
 

Calculate Jitter

Once you have entered the data into the utility or have loaded example data, click/tap the Calculate Jitter button to get the results.
 
 

4 — Results

The utility will calculate the following measurements:
  • Phase Jitter (fs)
  • Period Jitter (ps)
  • Cycle-to-Cycle Jitter (ps)
The recommended Silicon Labs devices that meet the jitter requirement specified will appear in a list. Click on the part number link for additional product information.
Note that only a subset of devices are listed in the recommended products summary. Other Silicon Labs products may meet this jitter requirement. Jitter specifications are summarized in the Product Matrix tab accessible via the part number links.
 
 

Additional Resources

Silicon Labs offers the industry's broadest portfolio of clocks and oscillators for communications, computing, consumer and broadcast video applications. Our timing IC products leverage patented DSPLL, MultiSynth and silicon oscillator technologies to eliminate expensive discrete components while improving performance, minimizing board space and simplifying system design.