What are you looking for?
Two main types of crystal oscillators: active crystal oscillators and passive crystal oscillators
Self-oscillation characteristics of active crystal oscillators and usage requirements of passive crystal oscillators. The content involves the internal structure of crystal oscillators, especially the piezoelectric effect of quartz crystals and their role in mechanical vibration.
· Classification of crystal oscillators
Generally, crystal oscillators are divided into two types: active crystal oscillators and passive crystal oscillators.
Active crystal oscillators are also called crystal oscillators, Oscillator;
Passive crystal oscillators are also called passive crystals, Crystal, crystal resonators.
Simply put, active crystal oscillators can output oscillation signals when they are powered on; passive crystals must add additional circuits to oscillate.
Active crystal oscillators
The above classification is from the perspective of use. From the perspective of internal structure, active crystal oscillators integrate drive circuits (such as amplifiers, load capacitors, etc.) on the basis of passive crystal oscillators, and realize the functions of signal amplification and stable output through packaging. Passive crystal oscillators play the role of frequency reference in the circuit, while the drive circuit further optimizes and standardizes the output signal so that it can meet a wider range of application needs. Due to the complexity of the integration and packaging of the driving circuit, the manufacturing cost of active crystal oscillators is usually higher than that of passive crystal oscillators.
Active crystal oscillator structure diagram
It can be understood that the active crystal oscillator is based on the reference oscillation frequency provided by the passive crystal oscillator, and further improves the function through additional circuits to form a plug-and-play oscillation signal output device. Only power is provided, and the active crystal oscillator can output a stable frequency signal, thereby simplifying the design of downstream circuits.
