A voltage controlled crystal oscillator (VCXO) is an electronic oscillator whose oscillation frequency is controlled by the externally applied input voltage. The applied voltage determines the instantaneous frequency of oscillation. The basic circuit of the VCXO includes a standard crystal oscillator as well as an electronic means of adjusting the frequency, generally achieved by means of diodes. Say no to plagiarism. Get a tailor-made essay on “Why Violent Video Games Should Not Be Banned”? Get Original Essay Generally, the oscillation frequency ranges from 30 ppm/volt to 50 ppm/volt. Typically, VCXO is in this frequency range. The frequency cannot be pushed too far because as the capacitance increases, the performance activity of the crystal decreases. They are widely used in broadcast and telecommunications equipment. They are used to design signals for clock generation. They are typically used in narrow-band phase-locked phases to provide frequency variations. Settings Frequency: This is usually specified in MHz for frequencies above 1.0 MHz or in kHz below. It must be specified with the correct number of decimal places to allow the manufacturer to determine the required frequency. Bottom line: VCXOs are required for a number of applications. Some may be used to drive different forms of logic, while others may be needed for analog applications. Therefore, output requirements are an important part of the overall specification. Frequency Stability: The base frequency stability of VCXOs is typically specified for an ambient temperature of 20°C and with the voltage control point set to its center value. Frequency is specified in terms of parts per million, ppm. Standard stability specifications are typically ±25 ppm, ±50 ppm and ±100 ppm. Supply voltage: It is necessary to specify the supply voltage to ensure that it operates within the unit for which it is intended. Ideally it should be able to operate outside of the power supply's intended tolerance so that any slight mismatch is not a problem. Operating Temperature Range: Most units have an operating temperature range over which they will operate. As a result, it is necessary to specify a range for the VCXO. There are three main ranges: 0 - 70°C - Often referred to as the commercial temperature range. It is normally satisfactory for operation in office or laboratory environments. -10 - + 70°C - Industrial range required where temperature ranges may fluctuate more widely. -40 - +85°C - this is close to the military range (normally -40 to +125°C) and is necessary when much wider temperature ranges are required. For example for equipment that can be used externally. Pullability: Pullability is the frequency range over which the VCXO can be pulled for a given change in control voltage. . It is specified in terms of parts per million, ppm, for a given voltage. As expected, higher pullability values ​​give a wider tuning range, but VCXOs will offer smaller pullability levels providing greater stability and lower phase noise. Keep in mind: this is just a sample. Get a personalized paper now from our expert writers. Get a custom essayPackage: It is necessary to specify the package because VCXOs come in many forms and various options may be available for mounting..