A 12 crystal oscillator is an electronic oscillator circuit that uses the mechanical resonance of a vibrating crystal of piezoelectric material to create an electrical signal with a precise frequency.
This frequency is commonly used to keep track of time, as in quartz wristwatches, to provide a stable clock signal for digitalintegrated circuits, and to stabilize frequencies for radio transmitters and receivers.
The most common type of piezoelectric resonator is the quartz crystal, so oscillator circuits incorporating them became known as crystal oscillators, but other piezoelectric materials including polycrystalline ceramics are used in similar circuits.
A crystal oscillator, particularly one made of quartz crystal, works by being distorted by an electric field when a voltage is applied to an electrode near or on the crystal.
This property is electrostriction or inverse piezoelectricity. When the field is not available, the quartz – which oscillates at a precise frequency – generates an electric field as it returns to its previous shape, and this can generate a voltage.
12 Mhz Crystal Oscillator | Quartz crystal Features
The result is that a quartz crystal behaves like an RLC circuit.
Quartz crystals are available in frequencies from a few tens of kilohertz to hundreds of megahertz. More than two billion crystals are manufactured annually. Most are used for consumer devices such as wristwatches, clocks, radios, computers, and cell phones.
Quartz crystals are also applicable inside test and measurement equipment, such as counters, signal generators, and oscilloscopes.
There are different types of oscillator electronic circuits such as Linear oscillators – Hartley oscillator, Phase-shift oscillator, Armstrong oscillator, Clapp oscillator, Colpitts oscillator, and so on, Relaxation oscillators – Royer oscillator, Ring oscillator, Multivibrator, and so on, and Voltage Controlled Oscillator (VCO).
crystal oscillators are used in the microprocessors and microcontrollers for providing the clock signals. Let us consider 8051 microcontroller for which an external crystal oscillator circuit of the 12MHz crystal oscillator is essential, even though (based on model) 8051 microcontroller is capable to run at 40 MHz (max). 8051 requires 12 clock cycles for one machine cycle, such that to give effective cycle rate at 1MHz (considering 12MHz clock) to 3.33MHz (considering maximum 40MHz clock). This crystal oscillator is used to generate clock pulses required for the synchronization of all the internal operations.