Voltage Controlled Crystal Oscillators
Durable VCXOs with Stable Temperature Control
Choosing the right type of frequency control components for your PCB design can be a difficult task, and one that needs to be given much care and thought. Finding an oscillator that satisfies your design specifications can make or break your entire project. If you have an application that requires a stable, dependable clock signal plus the ability to fine-tune your frequency source, then a voltage-controlled crystal oscillator (VXCO) is likely going to be the oscillator you’ll want to choose.
VCXOs was last modified: May 20th, 2024 by
| Part Number | Support Docs | Type | Package Size | Supply Voltage | Output | Frequency | Stability | Operating Temperature | |
|---|---|---|---|---|---|---|---|---|---|
 | ECXV-P | Datasheet Support Docs | VCXO | 2.50mm x 2.00mm, 3.20mm x 2.50mm, 5.00mm x 3.20mm, 7.00mm x 5.00mm | 2.5V, 3.3V | LVPECL | 10 MHz ~ 1500 MHz | ±25ppm | -40°C ~ 105°C, -40°C ~ 85°C |
| ECXV-L | Datasheet Support Docs | VCXO | 2.50mm x 2.00mm, 3.20mm x 2.50mm, 5.00mm x 3.20mm, 7.00mm x 5.00mm | 2.5V, 3.3V | LVDS | 10 MHz ~ 1500 MHz | ±25ppm | -40°C ~ 105°C, -40°C ~ 85°C |
| ECXV-H | Datasheet Support Docs | VCXO | 2.50mm x 2.00mm, 3.20mm x 2.50mm, 5.00mm x 3.20mm, 7.00mm x 5.00mm | 2.5V, 3.3V | HCMOS | 10 MHz ~ 250 MHz | ±25ppm, ±50ppm | -40°C ~ 105°C, -40°C ~ 85°C |
| ECS-VXO-97 | Datasheet Support Docs | VCXO | 7.00mm x 5.00mm | 5.0V | HCMOS | 8 MHz ~ 40 MHz | ±30ppm, ±50ppm, ±75ppm, ±100ppm | -10°C ~ 60°C |
| ECS-VXO-75 | Datasheet Support Docs | VCXO | 7.00mm x 5.00mm | 5.0V | HCMOS | 3 MHz ~ 77.760 MHz | ±50ppm | -10°C ~ 70°C |
| ECS-VXO-73 | Datasheet Support Docs | VCXO | 7.00mm x 5.00mm | 3.3V | HCMOS | 3 MHz ~ 77.76 MHz | ±50ppm | -10°C ~ 70°C |
 | ECS-2532VXO | Datasheet Support Docs | VCXO | 3.20mm x 2.50mm | 2.8V | HCMOS | 2 MHz ~ 54 MHz | ±30ppm | -10°C ~ 70°C |
Achieve Variable Frequency Output with VCXOs from ECS Inc.
Like other types of crystal oscillators, VCXOs oscillate at a frequency that is determined by the size and shape of the crystal being used in the component. However, what sets the VCXO apart is that the frequency can be adjusted within a narrow range by an external voltage source. This offers some pullability when it comes to output frequency, making it useful for a variety of applications. VCXOs are critical to the proper function of discrete phase-locked loops (PLL) and frequency modulation (FM) systems. Using what’s known as a varactor diode – which is essentially a voltage variable capacitor – one is able control and maintain the frequency of the oscillator crystal. The capacitance of these varactor diodes is inversely proportional to the voltage being applied.
Considerations When Choosing the Best VCXO
There are several factors that warrant some thought before choosing the VCXO that will best suit your design needs, the first of which is pullability. As we mentioned previously, pullability refers to frequency modulations from a crystal unit’s inherent frequency, which can be achieved by applying external voltage. Pullability is measured in parts per million (ppm) and impacts the tuning range of a crystal. Higher pullability metrics result in a wider tuning range; however, oscillators with smaller pullability numbers have lower phase noise and greater stability.
In a similar vein, you’ll also want to consider a component’s absolute pulling range, or APR. The APR of a VCXO is the guaranteed deviation from the crystal’s natural frequency when the maximum and minimum levels of voltage are applied. Calculating APR also includes aging and stability of the crystal component.
You’ll also want to take into account things like what output options, package sizes, control voltage, deviation and more. ECS Inc.’s oscillator products, including VCXOs, are available in a wide range of frequencies, voltages and output options. Output logic configurations consist of HCMOS, LVDS and LVPECL. Voltage-controlled crystal oscillators can be supplied in both surface mount device (SMD) and through hole packages.
For even more information about voltage controlled crystal oscillators, check out the technical guides like “What is a VCXO? Voltage Controlled Crystal Oscillator.”
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Electronic Component Solutions to Fit Your Design
Get in touch with a sales representative if you need more information about VCXOs or have questions about a specific requirement in your application design. Contact the ECS engineering team at engineering@ecsxtal.com for assistance with products, board respins and any additional questions. Search our online resource library for more information about our oscillators and their applications.