BQ35100: Short Trend Average and Long Short Trend Average values

Hi All,

1)  I'm testing the Gas Gauging BQ35100 and I've obtained these values on BQSTUDIO:

Short Trend Average = 66783 

Long Trend Average = 66594

Measured Z = 211 mOhms

Scaled R = 266 mOhms

2) If I take the mathematical expressions on §5.3.2 in TRM :

Short Trend Average = Impedance × 1/DF1 + Previous Impedance × (1–1/DF1)

Long Trend Average = Impedance × 1/DF2 + Previous Impedance × (1–1/DF2)

Where:

DF1 (50) and DF2 (100) are the time constants of the moving average

3) So the calculations are :

Short Trend Average = 0.211× 1/50 + 0.234 × (1–1/50) = 233.54 mOhms

Long Trend Average = 0.211× 1/100 + 0.234 × (1–1/100) = 233.77 mOhms

Why are the theoretical calculation not the same with the values of BQStudio registers ?

BR

Loïc