I was hoping for some confirmation for the TUE calculation.
ADS124S08 DS specifies the following, for full-temp, PGA = enabled and Gain = 1~8
(Convert all to voltages in next step)
| Error Sources (MAX) per Datasheet | ||
| Gain Error | 120 | PPM |
| Gain Error Drift | 4 | PPM/℃ |
| Offset Error | 120/GAIN = 30 | uV |
| Offset Error Drift | 200 | nV/℃ |
| INL | 15 | PPMfsr |
My question is, for the TUE calculations you need to know the FSR.
Assuming the reference to be 1.5V, the FSR = ±VREF / GAIN, right?
So with GAIN = 4, the FSR is ±1.5V/4 = ±0.375V = 0.75V
Using 0.75V as FSR to calculate the TUE gives...
| Error Sources (MAX) converted to voltage | ||
| Gain Error | 0.000090000 | V |
| Gain Error Drift | 0.000150000 | V |
| Offset Error | 0.0000300 | V |
| Offset Error Drift | 0.00001 | V |
| INL | 0.00001125 | V |
Then we add the errors to separate into Gain, Offset, and INL
| Total Gain Error | 0.000240 | V |
| Total Offset Error | 0.00004 | V |
| INL | 0.00001125 | V |
Then we calculate TUE (sum-of-squares)
| TUE | 0.00024357 | V |
Am I doing this correctly to calculate worst-case TUE?
Thanks
Darren
