Trim Effect: Control Voltage Freq Skew
Fig 1: The freq. vs. temp performance of one DUT at different control voltage set points.
What is Trim Effect?
Trim Effect is the distortion of an oscillator's frequency vs. temperature performance caused by changes in control voltage. This happens because moving the control voltage away from its central set point alters the load capacitance that the crystal experiences. As a result, the frequency versus temperature performance of the crystal shifts relative to its performance at another control voltage set point.
Why is Trim Effect Important?
Trim Effect can lead to system-level problems by impacting frequency accuracy over temperature. Since all oscillators age, many users apply control voltage adjustments to correct for this natural aging process. However, gradually shifting the control voltage over time can unintentionally skew the oscillator's temperature performance. In fact, this unintended effect can sometimes make performance worse than the natural aging would have caused.
Why Test for Trim Effect?
Testing is essential to ensure the oscillator meets the required performance specifications, particularly in high-precision applications like defense and aerospace. ERD offers tailored test profiles across a wide range of temperatures for different oscillator types, ensuring your system remains compliant and optimized.
Leave a comment