Release date:2020-06-15
With the rapid development of information technology, miniaturized products are more and more popular. The same is true in the crystal oscillator industry. As more and more electronic devices choose to use small, thin, and thin chip crystal oscillators, the range of applications for plug-in crystal oscillators is decreasing. Today Hui Yuan will discuss with you how to distinguish the position direction of SMT crystal oscillator.
I. What is an SMT crystal oscillator?
Crystal vibration is one of the components of quartz crystal. Quartz crystal resonators, quartz crystal oscillators and quartz crystal filters are all quartz crystal components. Quartz crystals are piezoelectric crystals. When a piezoelectric crystal is squeezed or stretched in a particular direction, its two ends generate different charges. According to the different effects, it can be divided into positive piezoelectric effect and negative piezoelectric effect. SMT crystal oscillator is mainly used in the clock module in the circuit to provide the corresponding clock reference, the common application is mainly embedded design, such as FPGA, DSP and other development board.
What is the difference between a passive crystal oscillator and an active crystal oscillator?
Common SMT crystal oscillator can be divided into passive and active crystal oscillator. Passive crystal oscillators usually have no direction, but have one pin. How do you distinguish passive crystal oscillator from active crystal oscillator pins?
The 2-pin SMT crystal oscillator must be passive, the 4-pin SMT crystal oscillator must be passive or active, and the 4-pin SMT crystal oscillator must be active.
How to distinguish the position direction of SMT crystal oscillator?
Passive crystal oscillators usually have no direction. For four legs, only two are functional feet, with the other two dangling for GND connections. In the case of an active crystal oscillator, the active crystal oscillator is usually imprinted above the direction of the footnote (the lower left corner of the point). Common 4-pin SMT crystal oscillator packages include 1.6 * 1.2mm, 2.0 * 1.6mm, 2.5 * 2.0mm, 3.2 * 2.5mm, 3.0 * 1.5mm, 5.0 * 3.2mm, 7.0 * 5.0mm, etc.
