Documentation sections

Phase Noise to Jitter Converter

POSThttps://rftools.io/api/py/v1/calculate

Slug phase-noise-to-jitter. Convert oscillator phase noise (dBc/Hz) to RMS jitter in ps and ADC SNR limit. Integrate over offset frequency range for clock design. Free, instant results.

Inputs

Send every one of these in inputs, in the units shown. Most are required: a call without one is refused (400) and costs nothing; one the calculator can do without takes the default shown. An input outside its range is still computed and flagged in the provenance.

Inputs of phase-noise-to-jitter
Name	Unit	Range	Default	Description
carrierFreqnumber	MHz	at least 0.001	100	Oscillator carrier frequency in MHz
phaseNoisenumber	dBc/Hz	at most 0	-120	Single-sideband phase noise spectral density at a representative offset
offsetFreqLownumber	kHz	at least 0.001	1	Lower integration limit for phase noise bandwidth
offsetFreqHighnumber	kHz	at least 1	10000	Upper integration limit for phase noise bandwidth
profileModenumber	none	0 … 1	0	Multi-point integrates a four-point L(f) profile instead of one flat levelOne of: 0 Single flat level · 1 Multi-point profile
offset2number	kHz	at least 0.001	10	Offset Point 2
pn2number	dBc/Hz	at most 0	-140	Phase Noise Point 2
offset3number	kHz	at least 0.001	100	Offset Point 3
pn3number	dBc/Hz	at most 0	-155	Phase Noise Point 3
offset4number	kHz	at least 0.001	1000	Offset Point 4
pn4number	dBc/Hz	at most 0	-165	Phase Noise Point 4

Outputs

Returned in values, by key. A value that is unbounded or undefined is null.

Outputs of phase-noise-to-jitter
Field	Unit	Description
rmsJitterheadline	ps	RMS Jitter
cycleToCycleJitter	ps	Cycle-to-Cycle Jitter
phaseNoisePower	dBc	Integrated Phase Noise Power
rmsPhaseError	deg	RMS Phase Error
adcSnrLimit	dB	Maximum achievable ADC SNR limited by clock jitter at this carrier frequency
pointsIntegrated	none	The L(f) points inside the integration band, the band's end where the last level is held included; a point outside it is left out of the integral

Calling it

Calculate: one call, the request and response in full, and its errors.
Batch: this calculator with others, or a sweep, in one request.
Solve for a target: the value of one input that brings an output to a target.

curl -X POST https://rftools.io/api/py/v1/calculate \
  -H "X-API-Key: $RFTOOLS_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "slug": "phase-noise-to-jitter",
    "inputs": {
      "carrierFreq": 100,
      "phaseNoise": -120,
      "offsetFreqLow": 1,
      "offsetFreqHigh": 10000,
      "profileMode": 0,
      "offset2": 10,
      "pn2": -140,
      "offset3": 100,
      "pn3": -155,
      "offset4": 1000,
      "pn4": -165
    }
  }'

import rftools

client = rftools.Client()  # reads RFTOOLS_API_KEY, or the key `rftools login` saved

result = client.calculate("phase-noise-to-jitter", {
    "carrierFreq": 100,
    "phaseNoise": -120,
    "offsetFreqLow": 1,
    "offsetFreqHigh": 10000,
    "profileMode": 0,
    "offset2": 10,
    "pn2": -140,
    "offset3": 100,
    "pn3": -155,
    "offset4": 1000,
    "pn4": -165,
})
print(result.values)
print(result.warnings, result.provenance.formula_ref)

const response = await fetch("https://rftools.io/api/py/v1/calculate", {
  method: "POST",
  headers: {
    "X-API-Key": process.env.RFTOOLS_API_KEY,
    "Content-Type": "application/json",
  },
  body: JSON.stringify({
    "slug": "phase-noise-to-jitter",
    "inputs": {
      "carrierFreq": 100,
      "phaseNoise": -120,
      "offsetFreqLow": 1,
      "offsetFreqHigh": 10000,
      "profileMode": 0,
      "offset2": 10,
      "pn2": -140,
      "offset3": 100,
      "pn3": -155,
      "offset4": 1000,
      "pn4": -165
    }
  }),
});
console.log(response.status, await response.json());

package main

import (
	"bytes"
	"fmt"
	"io"
	"net/http"
	"os"
)

func main() {
	body := []byte(`{
	  "slug": "phase-noise-to-jitter",
	  "inputs": {
	    "carrierFreq": 100,
	    "phaseNoise": -120,
	    "offsetFreqLow": 1,
	    "offsetFreqHigh": 10000,
	    "profileMode": 0,
	    "offset2": 10,
	    "pn2": -140,
	    "offset3": 100,
	    "pn3": -155,
	    "offset4": 1000,
	    "pn4": -165
	  }
	}`)
	req, err := http.NewRequest("POST", "https://rftools.io/api/py/v1/calculate", bytes.NewReader(body))
	if err != nil {
		panic(err)
	}
	req.Header.Set("X-API-Key", os.Getenv("RFTOOLS_API_KEY"))
	req.Header.Set("Content-Type", "application/json")
	res, err := http.DefaultClient.Do(req)
	if err != nil {
		panic(err)
	}
	defer res.Body.Close()
	out, _ := io.ReadAll(res.Body)
	fmt.Println(res.Status, string(out))
}

application/json

{
  "slug": "phase-noise-to-jitter",
  "values": {
    "rmsJitter": 7.117269544002596,
    "cycleToCycleJitter": 10.065339116193446,
    "phaseNoisePower": -50.00043431619807,
    "rmsPhaseError": 0.2562217035840934,
    "adcSnrLimit": 46.990134359558255,
    "pointsIntegrated": 2
  },
  "warnings": [],
  "errors": [],
  "provenance": {
    "method": "calculator:phase-noise-to-jitter",
    "version": "api@3f2c1a9b04de",
    "formulaRef": "A Simple Model of Feedback Oscillator Noise Spectrum, D. B. Leeson, Proc. IEEE 54(2), pp. 329–330 (1966)",
    "assumptions": [],
    "validRange": {
      "status": "inside",
      "bounds": {
        "carrierFreq": {
          "min": 0.001,
          "max": null,
          "unit": "MHz"
        },
        "phaseNoise": {
          "min": null,
          "max": 0,
          "unit": "dBc/Hz"
        },
        "offsetFreqLow": {
          "min": 0.001,
          "max": null,
          "unit": "kHz"
        },
        "offsetFreqHigh": {
          "min": 1,
          "max": null,
          "unit": "kHz"
        },
        "profileMode": {
          "min": 0,
          "max": 1,
          "unit": ""
        },
        "offset2": {
          "min": 0.001,
          "max": null,
          "unit": "kHz"
        },
        "pn2": {
          "min": null,
          "max": 0,
          "unit": "dBc/Hz"
        },
        "offset3": {
          "min": 0.001,
          "max": null,
          "unit": "kHz"
        },
        "pn3": {
          "min": null,
          "max": 0,
          "unit": "dBc/Hz"
        },
        "offset4": {
          "min": 0.001,
          "max": null,
          "unit": "kHz"
        },
        "pn4": {
          "min": null,
          "max": 0,
          "unit": "dBc/Hz"
        }
      },
      "outside": [],
      "model": null
    },
    "computedAt": "2026-09-24T14:05:11.003Z",
    "inputs": {
      "carrierFreq": 100,
      "phaseNoise": -120,
      "offsetFreqLow": 1,
      "offsetFreqHigh": 10000,
      "profileMode": 0,
      "offset2": 10,
      "pn2": -140,
      "offset3": 100,
      "pn3": -155,
      "offset4": 1000,
      "pn4": -165
    },
    "seed": null,
    "elapsedSeconds": 0.003
  }
}

{
  "detail": [
    {
      "type": "float_parsing",
      "loc": [
        "body",
        "inputs",
        "carrierFreq"
      ],
      "msg": "Input should be a valid number, unable to parse string as a number",
      "input": "abc"
    }
  ]
}

An input sent as text. Nothing was counted.

{
  "detail": "More than 120 requests in 60 seconds from this address.",
  "errorKind": "rate_limited",
  "limit": 120,
  "windowSeconds": 60,
  "upgradeUrl": "https://rftools.io/pricing/"
}

Too many requests in a minute, with Retry-After.

Same inputs on the calculator pagePhase Noise to Jitter Converter, at these values