Hi all
I'm using bq51013b and are currently trying to do a FOD calibration using the "FOD Calibration" tool (sluc577).
Unfortunately, the resulting "Model Errors" are until -550mV and not correctable within the Vos limitations. Following the measurements for RFOD = 196, ROS = 1M, RLIM = 80 for a load from 0 to 525mA in 25mA steps.
VRECT (V) ILOAD (mA) VOUT (V) PPT (mW) PPR (mW) VFOD (mV) 7.09 0 5.016 0 0 0 7.07 25 5.009 0 195 17.4 7.05 50 5.001 0 391 34.9 7.08 75 4.994 0 625 52.3 6.34 100 4.988 0 742 69.8 6.25 126 4.98 0 742 88.3 6.26 150 4.96 0 1016 105 5.58 175 4.96 0 1055 122 5.57 200 4.96 0 1289 139 5.53 225 4.95 0 1406 159 5.49 250 4.95 0 1563 175 5.52 277 4.94 0 1719 191 5.51 300 4.94 0 1875 210 5.51 326 4.93 0 2031 230 5.46 352 4.93 0 2188 247 5.14 375 4.92 0 2305 265 5.08 402 4.92 0 2422 284 5.05 426 4.91 0 2578 301 5.04 447 4.90 0 2734 317 5.03 476 4.89 0 2891 337 5.03 503 4.88 0 3125 358 5.12 527 4.88 0 3242 366
PPR monitoring is done using a self-developed tool. It expects max_pwr = 10 and pwr_class = 0. A PPR value of 0x53 for example results in 3.242W.
Do I may have a measurement error or could there be an error in my design? I can't find instructions in the User Manual to handle this issue.
How do you calculate "Model Error"? Can I might get the old calibration sheet (SLUA674A) to determine it?
Kind regards
Christian Frick
