Relationship between differential crystal oscillator and quartz crystal oscillator

In recent years, in the network era of rapid development of information, face recognition, traffic violation detection and data upload are all centered on image data transmission, which requires high-speed transmission of sensing data. However, "differential transmission" is usually used in high-speed transmission systems. With the increasing speed of modern life, even in the crystal oscillator which becomes the reference clock source for data transmission, the demand for differential output quartz crystal oscillator (hereinafter referred to as differential crystal oscillator) continues to increase
Generally speaking, single-phase output is called quartz crystal oscillator and is mainly represented by sine wave or CMOS wave type (rectangular wave). Sheared sine wave output has a waveform similar to rounded rectangle and is often used in RF circuits because it suppresses unnecessary harmonics. TCXO (temperature compensated crystal oscillator) It is called the product of clipping sine wave output. Since CMOS wave output is the signal output of logic electronics corresponding to digital signal processing, it is conducive to the transmission of digital signals and used for clocks, such as CPU. What do you know about differential crystal oscillator? What are the characteristics of the output wave of differential crystal oscillator?
The small amplitude waveform is easily affected by noise. For example, in the + 3.3V CMOS waveform (in the threshold + 1.6V determination), even if there is + 1V noise, the signal will not be misidentified. However, if there is + 1V GND noise in the + 1.8V CMOS waveform (in the threshold + 0.9V determination), the signal exceeding the threshold will be reversed and misidentified, Differential signals are effective as a means to prevent erroneous identification in such small amplitude waveforms. Differential signals are characterized by inverse phase waveforms with phase inversion output respectively from one oscillator. One oscillator has phase inversion. Because signals with equal amplitude and opposite phase are transmitted in pairs and have great differences, they are not easy to be affected by external noise and GND
Even if the following differential crystal oscillator is affected by GND noise, when the end of the output is cancelled, it is displayed as a signal without noise, and the single output oscillator is affected by noise. In this way, the influence of noise can be prevented by using differential crystal oscillator. What are the advantages of differential crystal oscillator? What should we pay attention to when using?
The advantage of differential signal is that it does not produce oscillation when used at the end. Relatively speaking, a single output signal will not end, so it is easy to produce frequency, resulting in high-profile wave observation, EMI, etc. when used as differential signal, it should be noted that the symmetry of each signal waveform is very important. If there is delay (skew) in a waveform or the waveform is not aimed, Common mode noise that will affect the signal quality such as EMI. A single output quartz crystal oscillator is used. The single output signal can accept waveform conversion on the system [c side to generate a differential signal (waveform), but there is no delay (skew) between waveforms The circuit will be difficult to design, so it is designed as a special differential crystal oscillator. If the quartz crystal oscillator is used, the skew signal can be obtained between the waveforms, which can reduce the risk of wrong operation of the system. In addition, DTV (double data rat) is used to transmit data when the rising edge and lower edge of the clock are used in the high-speed D23 memory However, in terms of system IC, it is difficult to obtain the waveform of the vertical edge. In this field, the respective rising edges of the output signal of the differential crystal oscillator can also be used to realize the DTV function

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Keyword：Differential crystal oscillator   quartz crystal oscillator   temperature compensated crystal oscillator   CMOS wave   DTV   Commax-Tech Electronic