Active crystal oscillator and passive crystal oscillator (how to distinguish between active and passive crystals)

Mar 12,2024
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Table of contents for this article

What is the difference between transistors and crystal oscillators

How to define active crystal oscillator pins

Does an active crystal oscillator have split polarity

What is an active crystal oscillator and what is its function

Is the crystal oscillator of 51 microcontroller active or passive

How to distinguish between active crystals and passive crystals

What is the difference between transistors and crystal oscillators

The difference between transistors and crystal oscillators is that transistors can amplify current or voltage signals or act as power switches. And crystal oscillators can only cause oscillations in current or voltage. It cannot be enlarged.

Transistors mainly refer to diodes, transistors, field-effect transistors, thyristors, etc., and the main materials are silicon and germanium.

The component of crystal oscillator is quartz. It is made based on its piezoelectric effect and is mainly used for oscillation and filtering.

That is to say, a transistor is a solid-state semiconductor device with various functions such as detection, rectification, amplification, switching, voltage stabilization, signal modulation, etc. Transistors, as a variable current switch, can control output current based on input voltage.

Quartz crystal oscillator is a quartz crystal resonator made of quartz material, commonly known as crystal oscillator. It plays a role in generating frequency, has stable and good anti-interference performance, and is widely used in various electronic products.

How to define active crystal oscillator pins

Active crystal oscillator pins are mostly four or more pins, and more often have four pin positions. Compared to passive four pin SMT oscillators, although passive SMT oscillators have four pins, only two are truly called functional pins, namely pin 1 and pin 3. The other two pins serve as fixing points, while the four pins of active oscillators are all functional pins. Guangruitai shares the definition of active oscillator pins:

Pin 1 suspended, pin 2 grounded, pin 3 output, pin 4 voltag

Does an active crystal oscillator have split polarity

1. A passive crystal oscillator is a non-polar component with two pins that requires the use of a clock circuit to generate an oscillation signal and cannot oscillate on its own. 2. An active crystal oscillator has four pins, making it a complete oscillator. In addition to quartz crystals, there are also transistors and resistive and capacitive components, which mainly depend on the circuit you apply. If there is a clock circuit, use passive, otherwise use active

What is an active crystal oscillator and what is its function

An active crystal oscillator, also known as an oscillator, has four pins and is a complete oscillator. In addition to quartz crystals, active crystal oscillators also have transistors and resistance capacitance components, so the size of active crystal oscillators is generally larger.

Active crystal oscillators are composed of quartz crystals, and their ability to be used as oscillators is based on the piezoelectric effect of quartz chips. When a certain electric field is applied to the two poles of a chip, the crystal will undergo mechanical deformation. If an alternating voltage is applied, the crystal will generate mechanical vibration, and mechanical deformation will also generate an alternating electric field.

The usage of active crystal oscillators includes one pin suspended, two pins grounded, three pins connected to output, and four pins connected to voltage. Find the marked pin and count counterclockwise, 1, 2, 3, 4, making sure the pin is facing downwards.

Crystal oscillators are commonly used in oscillation circuits as frequency selection components. Due to its precise frequency and high stability, crystal oscillators are often used as standard frequencies and pulse signal sources, and are widely used in communication, industrial control, embedded systems, and other fields, especially in embedded systems, providing clock pulses for the system.

Is the crystal oscillator of 51 microcontroller active or passive

Passive crystal oscillators are usually used, but active crystal oscillators can also be used, although their connections are different.

When using a passive crystal oscillator, it should be connected across the XTALI and XTALO of the microcontroller, and the two pins of the crystal oscillator should also be grounded through a 15-22p capacitor.

If an active crystal oscillator is used, the output pin of the crystal oscillator should be connected to the XTALI of the microcontroller, and the XTALO should be suspended.

How to distinguish between active crystals and passive crystals

A passive crystal oscillator is a non-polar component with two pins that requires the use of a clock circuit to generate oscillation signals and cannot oscillate on its own. Therefore, the term "passive crystal oscillator" is not accurate. The passive crystal oscillator reference circuit has poor signal quality and usually requires precise matching of peripheral circuits (capacitors, inductors, resistors, etc. used for signal matching). When replacing crystals with different frequencies, the peripheral configuration circuit also needs to be adjusted accordingly. It is generally recommended to use quartz crystals with higher accuracy and avoid using ceramic crystals with lower accuracy as much as possible.

An active crystal oscillator has 4 pins and is a complete oscillator. In addition to quartz crystals, it also has transistors and resistive and capacitive components, making it relatively large in size. The packaging of an active crystal oscillator has four pins, namely VCC (voltage), GND (ground), OUT (clock signal output), and NC (empty pin). Active crystal oscillator reference circuit: An active crystal oscillator does not require an internal oscillator of the CPU, with stable signals, good quality, and a relatively simple connection method (mainly used for power filtering, usually using a capacitor and inductor to form a filtering network, and using a small resistance at the output end to filter the signal), without the need for complexity.