This tool converts from crystal oscillator stability in terms of **Parts Per Million** (PPM) to the equivalent **Frequency** variation (Hz/kHz/MHz/GHz)

Enter

- PPM value
- Center Frequency (use the dropdown menu to select units)

The tool will provide the frequency variation and min and max values of frequency

🔁 Frequency to PPM

**Formula**

The frequency variation **df** on either side of the center frequency **F** is given by

**df = F*ppm*10 ^{-6}**

The maximum and minimum frequency are given by

**Fmax = F + df**

**Fmin = F – df**

**Example Calculation**

The following 10 MHz oscillator has a frequency stability of +/- 0.1 PPM

The oscillator can be used as a reference clock with a phase locked loop to generate a frequency of 1 GHz.

Enter these numbers (0.1 PPM and 1 GHz) into the calculator above to calculate a frequency variation of **+/- 25 kHz**. The minimum and maximum frequencies generated are **999.975 MHz** and **1000.025 MHz**, respectively.

**What is PPM?**

PPM, or parts per million, is a unit of measure used to describe small values of dimensionless quantities, such as the relative change in frequency or the concentration of a particular substance in a solution. In the context of frequency, PPM is used to describe the deviation or stability of a frequency source relative to its nominal value.

**The Importance of PPM in Frequency Measurements**

Frequency stability is essential in many applications, particularly in communications, where the accuracy of signal transmission and reception can critically impact performance. A frequency source might be specified with a stability of, for example, ±10 PPM, meaning it can vary by 10 parts per million from the nominal frequency. This variation can affect how systems synchronize or how accurately signals are modulated or demodulated.

**Applications of PPM to Frequency Conversion**

Understanding and applying PPM to frequency conversion is vital in several technical fields:

**Telecommunications:**Ensures compatibility and synchronization in networks and communication systems.**Broadcasting:**Maintains frequency standards for clear and reliable transmission.**Satellite Communications:**Helps in precise navigation and data transmission.**Scientific Instruments:**Ensures accuracy in measurements and operations that depend on stable frequency references.