Written by David Meaney, Vice President of Global Technical Sales and Marketing at ECS Inc.

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The ECOC-2522 series of oven-controlled crystal oscillators, or OCXOs, are designed to generate a very clean signal and stabile clocking signal. The series has the capability to offer frequencies from 2 MHz to 100MHz. For a full list of independent frequencies, please reference the list of developed frequencies below. ECS Inc.’s ECOC-2522 OCXOs feature an SC cut high Q crystal with an internal thermistor to maintain the quartz crystal and oscillator circuits at a constant temperature. This creates a stable environment and prevents the oscillator from experiencing frequency drift. OCXOs provide a highly stable, clean clocking source for telecommunications, cellular base stations, data communications, instrumentation, test and measurement equipment and more where tight frequency stability and signal quality is critical.  

Developed Frequencies

  • 10.0 MHz
  • 12.8 MHz
  • 13.0 MHz
  • 16.384 MHz
  • 20.0 MHz
  • 38.4 MHz
  • 38.8 MHz
  • 40.0 MHz
  • 100 MHz

One of the performance functions of the ECOC-2522 is the voltage control (Vc) port which provides a means to calibrate the output frequency post reflow. The ECOC-2522 supplies a regulated DC voltage output on pin #2 V Ref. The value of this voltage is dependent upon the supply voltage bias. For a 5.0V Vdd, the Vref value will be +4.50V ±0.2V. Similarly when Vdd = 3.3V VDD, the Vref value will be +2.80V ±0.2V. See the following figures for the two preferred methods for utilizing the voltage control port (Vc).  

Figure (1) depicts that the simplest way to utilize the Vref output is to connect a potentiometer between Vref and GND. The wiper of the potentiometer should then be connected to the Vc port) of the OCXO. This way, the DC Voltage value at the Vc port can be adjusted by varying the position of the wiper.   

  

Figure (2) depicts another way to achieve a similar result by using two resistors as a potential divider approach. The Vc voltage will be determined by Vc = (R2 / (R1+R2)) Vref. As shown, R2 can either be fixed or a variable resistor.   

Resistor values for a 3.3V supply may vary but a positive starting point would be when R1equals 6.98 kΩ and when R2 equals 10.00 kΩ. Ideal resistor values for a 5.0V supply might be when R1 equals 8.06 kΩ and when R2 equals 10.00 kΩ. If a potentiometer is used in place of R2 for either the 3.3V or 5.0V supply, the wiper should be connected to the Vc port to provide a variable resistance. Note that the bypass capacitors on both the Vdd port and the Vc port are suggested values to help improve noise suppression.  

Performance of the OCXO ECOC-2522 series is world class. Test setups for both the HCMOS output ECOC-2522 C and sine wave output ECOC-2522 S components are depicted below.   

Below are the phase noise charts and graphs from three 100MHz test oscillators.   

ECOC-2522-100.000-3FC Phase Noise and Jitter  

ECOC-2522-100.000-3FC Phase Noise and Jitter 

ECS Inc. International is committed to offering our customers the best frequency control products on the market. Today, that means taking advantage of the high precision quality “Q” and stability that quartz-based oscillators can offer. 

Please contact us if you need additional information or have a specific requirement in your application.


ECS Inc. International
15351 West 109th Street
Lenexa, KS 66219
Tel: 913-782-7787
Toll Free: 1-800-237-1041
Fax: 913-782-6991

Voltage Control and Voltage Reference for the ECOC-2522 OCXO was last modified: October 12th, 2023 by ECS Inc.