Referring to Figure 1-1 for the circuit example, we can calculate the error from all sources which are
mentioned below.
Table 5-1 Reference Non-inverting Amplifier
(OPA828)
Error Source |
Error in ppm |
Input Offset Voltage |
140 |
Offset voltage drift |
60 |
Bias Current |
0.6 |
Offset Current |
0.3 |
Resistor Tolerance |
100.01 |
Resistor Tolerance Drift |
499.88 |
Total |
532.05 |
Table 5-2 Reference Buffer
(OPA828)
Error Source |
Error in ppm |
Input Offset Voltage |
140 |
Offset voltage drift |
60 |
Total |
152.32 |
Table 5-3 Reference Inverting Amplifier
(OPA828)
Error Source |
Error in ppm |
Input Offset Voltage |
210 |
Offset voltage drift |
90 |
Bias Current |
1.2 |
Offset Current |
0.6 |
Resistor Tolerance |
200.02 |
Resistor Tolerance Drift |
0.25 |
Total |
303.66 |
Table 5-4 R2R DAC (DAC11001A)
Error Source |
Error in ppm |
Integral Non Linearity |
1.9 |
Zero Code Error |
3.81 |
Zero Code Drift |
40 |
Gain Error |
10 |
Gain Error Drift |
40 |
Total |
57.95 |
Table 5-5 Voltage Reference
(REF6025)
Error Source |
Error in ppm |
Initial Error |
250 |
Temperature Coefficient Error |
200 |
Load Regulation |
75 |
Total |
525 |
Table 5-6 DAC Output Buffer
(OPA828)
Error Source |
Error in ppm |
Input Offset Voltage |
70 |
Offset Voltage Drift |
30 |
Total |
76.2 |