Part Number: UCD90120A
Hello Team,
A customer is having issue's with the UCD90120A and in-inaccuracies in current measurement.
I am also having some trouble with current measurements through the UCD90120A and the Fusion Digital Software.
I have a 0.005 ohm sense resistors connected to several of the MON inputs of the UCD90120A through INA214 sense amplifiers (Gain = 100). I have the Iout Cal Gain parameter for those “rails” set accordingly to 5000 milli-ohm.
At higher load currents, the values reported by Digital Fusion are very accurate, but at low-mid currents, error is terrible. At 99 mA, for example (which is 20% of full scale), error is -21%!
I also noticed that the resolution in the reported values is 15 or 16 mA. It should theoretically be 0.12 mA.
I am suspicious of a truncation error in the software.
Electronic Load Measurement [A] | Fusion Digital Reported Values [A} | Error |
0.009 | 0.031 | 240.7% |
0.020 | 0.031 | 59.0% |
0.050 | 0.031 | -37.4% |
0.099 | 0.078 | -21.1% |
0.199 | 0.188 | -5.6% |
0.299 | 0.281 | -6.1% |
0.373 | 0.391 | 5.0% |
0.376 | 0.406 | 8.0% |
0.379 | 0.406 | 7.3% |
0.385 | 0.406 | 5.5% |
0.395 | 0.406 | 2.7% |
0.397 | 0.406 | 2.4% |
0.398 | 0.391 | -1.8% |
0.398 | 0.406 | 2.0% |
0.400 | 0.391 | -2.2% |
0.401 | 0.391 | -2.5% |
0.403 | 0.391 | -2.9% |
0.404 | 0.391 | -3.3% |
0.407 | 0.406 | -0.2% |
0.422 | 0.422 | 0.0% |
0.498 | 0.499 | 0.1% |