Difference Between Crystal Oscillator and Frequency Synthesizer

Crystal Oscillator vs Frequency Synthesizer

In communication and transmission systems, you need to have a specific frequency that the transmitter and receiver will use in order to achieve the transmission of information. To achieve this you need to use something like crystal oscillators or frequency synthesizers. The main difference between a crystal oscillator and a frequency synthesizer is the number of frequencies that they can produce. A crystal oscillator uses the mechanical vibrations of a crystal in order to produce a resonant frequency that is very precise. But it can only produce the frequency that it was designed for. On the other hand, the more complex frequency synthesizer is able to produce a specific number of frequencies with identical steps.

Crystal oscillators became very popular when they came out because they provided an accurate and inexpensive timing system for watches where only a single frequency is needed. Crystal oscillators can be mass produced and have an error rate of one second in every few decades. Crystal oscillators are also used in other types of circuits that need a specific timing frequency and are very popular among hobbyists.

A frequency synthesizer is a more complex circuit but it doesn’t really produce its own frequency. It also has a crystal oscillator or other types of oscillators that will serve as the base frequency. The accuracy of the frequency synthesizer still depends on the oscillator that it uses.

The need for a frequency synthesizer stems from receivers that can be tuned to multiple frequencies; good examples of which are radios and TVs. You can use discrete crystal oscillators for each channel, but it is too costly and too bulky. A frequency synthesizer works by obtaining a base frequency and multiplying or dividing it to achieve the desired frequency.

It is very easy to distinguish whether you need a crystal oscillator or a frequency synthesizer just by looking a t your needs. If you only need a single frequency, a crystal oscillator should be adequate for your needs and is very cheap. If you need the ability to change multiple frequencies in your circuit, getting a frequency synthesizer may be cheaper than using multiple crystal oscillators.

Summary:

1. A crystal oscillator produces a single frequency while a frequency synthesizer produces a set number of frequencies
2. Frequency synthesizers often use a crystal oscillator

Sharing is caring!