Crystal Capload Equation in the datasheet of CY22050

Question: CapLoad = (CL - CBRD - CCHIP)/0.09375. Could you please explain the equation on the datasheet of CY22050?



The equation CapLoad = (CL - CBRD - CCHIP)/0.09375, shown in the datasheet, provides a calculation of the internal digital tuning capacitance used to achieve zero PPM.  In this equation:



  CL: The crystal-specific internal load capacitance.  This quantity can be found in the crystal datasheet.


  CBRD: The series combination of the capacitance seen from Xin and Xout pins due to external caps and to the board trace caps.


  CCHIP: Internal chip capacitance. 


  Upon entering the crystal load capacitance, CyberClocks automatically calculates the CapLoad value. Hence, the user does not need to worry about this.