Comparison of a Crystal Oscillator to a MEMS Oscillator
Crystal vs MEMS – Oscillator Performance
Abstract
The Selection of an oscillator for electronic devices and communications system equipment is a major factor affecting system performance. In this application note, we have measured and will compare two different types of oscillators:
1. A fundamental Quartz Crystal oscillator and
2. A MEMS (Mirco-Electro-Mechanical System) oscillator
Structure and Characteristics of Oscillators
A Crystal oscillator consists of a basic structure using a Quartz crystal in fundamental mode and a simple oscillator circuit.
In contrast, MEMS oscillators have a complex structure consisting of a resonator, a fractional-N PLL, and temperature compensation and manufacturing calibration. A MEMS oscillator uses a silicon resonator as the oscillating source and requires a PLL circuit to correct the frequency for manufacturing tolerances and temperature coefficient.
Comparison of Properties of Crystal Oscillators and MEMS Oscillators
We measured a Crystal oscillator and a MEMS oscillator and compared four parameters from each that are considered critical for the design of communication, industrial, and consumer
electronic devices.
1. Phase noise and phase jitter
2. Power consumption
3. Oscillator start up characteristics
4. Frequency temperature characteristics