SNLA385 September   2021 DP83561-SP , DP83620 , DP83630 , DP83640 , DP83822H , DP83822HF , DP83822I , DP83822IF , DP83825I , DP83826E , DP83826I , DP83843 , DP83847 , DP83848-EP , DP83848-HT , DP83848C , DP83848H , DP83848I , DP83848J , DP83848K , DP83848M , DP83848Q-Q1 , DP83848T , DP83848VYB , DP83848YB , DP83849C , DP83849I , DP83849ID , DP83849IF , DP83867CR , DP83867CS , DP83867E , DP83867IR , DP83867IS , DP83869HM

 

  1.   Trademarks
  2. 1Introduction
  3. 2IEEE Specification and How to Derive the Formula
  4. 3Formula Helper to Calculate Limit
  5. 4Conclusion and Summary
  6. 5References

Formula Helper to Calculate Limit

The following formula can be copied into a Microsoft® Excel file. With this helper the engineer can validate if the test equipment vendor is using the correct percent error formula:


GUID-20210719-CA0I-LTMF-5TQK-GRP7RPVLSHR8-low.png

Va = 695.89 mV

Vb = 708.24 mV

=100*((B2-0.5*(B1+B2))/(0.5*(B1+B2)))


GUID-20210719-CA0I-5WVL-Z9XS-HRQ3JGL3MVTV-low.png

Figure 3-1 Formula in Microsoft® Excel

The result in the Excel table cell B3 reports that the test result has been passed because it is below 1%. The test report from the test equipment vendor shows a failed test case. In this case the formula used in Figure 1-1 by the manufacturer is incorrect and out-of-date. When facing this situation, contact the test manufacturer for a software update.