Hi Team
the following TUE calculation is correct ?
FSR(Full Scale Range) = 2 x 1.467 x Vref = 2 x 1.467 x (VREFP pin ─ VREFN pin)
[ADS1605는 Vref = Max 3V recommanding]
= 2 x 1.467 x 3V = 8.802V. ==> So, ADC output code will be ± 4.401V.
1 LSB = FSR/2^16 = 8.802V/65536 = 134.308 uV
Offset Error = 0.05[%FSR] = 0.05/100 x 8.802V = 4.401 mV = 4.401 mV/134.308uV = ±32.77[LSB]
Offset Error Drift = 1 [ppmFSR/⁰C] = 1/10000 [%FSR/⁰C] = 1/10000 [%FSR/⁰C] x 65⁰C = 0.0065[%FSR] = 0.0065/100 x 8.802V = 0.57213mV= 0.57213mV/134.308uV = ±4.26[LSB].
[ |-40⁰C - 25⁰C | = 65⁰C,,,]
hence, in operating temp range of -40⁰C~85⁰C, Max Offset is ±(4.401mV + 0.57213mV) = ±4.973mV.
Gain Error = 0.25[%] = 0.25/100 x 8.802V = 22.005mV = 22.005 mV/134.308 uV = ±163.84[LSB]
Gain Error Drift = 10[ppm/⁰C] = 10/10000[%/⁰C] = 10/10000 x 65[%] = 0.065[%] = 0.065/100 x 8.802V = 5.721mV = 5.721mV/134.308uV = ±42.60[LSB]
[ |-40⁰C - 25⁰C | = 65⁰C,,,]
INL = ±0.75[LSB]
DNL = ±0.25[LSB]
therfore, TUE = Sqrt[(32.77+4.26)^2 + (164.84+42.6)^2 + 0.75^2 + 0.25^2]
= Sqrt[37.03^2 + 207.44^2 + 0.75^2 + 0.25^2]
= ±210.72[LSB] = 210.72[LSB] x 134.308uV = ±28.3 mV.
