Part Number:INA219
I am developing an application that uses the INA219B and noticed the bus voltage offset mentioned in other threads already. I am not using a filter, the shunt is 0.1 Ohm and I connected a DMM to Vin- to directly compare with the INA219 reading. BRNG = 1 (32V), no load applied.
I read in a thread that the INA219 bus voltage offset is (more or less) constant and could be corrected. In my measurements, the offset is not constant but it seems to follow a linear function and, with regression analysis, a correction function can be applied (as in the last three columns). My question: is the bus offset supposed to be constant or is the observed behaviour correct?
Thanks.
Slope | -0.001005742100229 |
Intercept | 0.028764918466064 |
DMM Vin- | INA219 | Diff | Err% | Corrected | Corr. Diff | Corr Err% |
1.0046 | 0.976 | 0.0286 | 2.85% | 1.00375454995217 | 0.000845450047826 | 0.08% |
2.0027 | 1.976 | 0.0267 | 1.33% | 2.00275071876194 | -5.07187619360749E-05 | 0.00% |
3.0038 | 2.98 | 0.0238 | 0.79% | 3.0057438703454 | -0.001943870345397 | -0.06% |
4.0015 | 3.976 | 0.0255 | 0.64% | 4.000740441452 | 0.000759558548002 | 0.02% |
5.0034 | 4.98 | 0.0234 | 0.47% | 5.00373278844178 | -0.000332788441779 | -0.01% |
6.0051 | 5.98 | 0.025099999999999 | 0.42% | 6.00272533657998 | 0.00237466342002 | 0.04% |
7.0077 | 6.988 | 0.0197 | 0.28% | 7.00971697955029 | -0.00201697955029 | -0.03% |
8.0076 | 7.988 | 0.019600000000001 | 0.24% | 8.00871133802427 | -0.001111338024272 | -0.01% |
9.0042 | 8.984 | 0.020200000000001 | 0.22% | 9.00370901544718 | 0.000490984552817 | 0.01% |
10.0032 | 9.984 | 0.0192 | 0.19% | 10.0027042790891 | 0.000495720910944 | 0.00% |
11.0009 | 10.984 | 0.0169 | 0.15% | 11.0017008501957 | -0.000800850195658 | -0.01% |
12.0052 | 11.988 | 0.017200000000001 | 0.14% | 12.0046907834044 | 0.000509216595603 | 0.00% |
13.0097 | 12.992 | 0.0177 | 0.14% | 13.0076805154647 | 0.002019484535282 | 0.02% |
14.0013 | 13.988 | 0.013300000000001 | 0.09% | 14.0026832215981 | -0.001383221598129 | -0.01% |
15.0029 | 14.988 | 0.014900000000001 | 0.10% | 15.0016758703105 | 0.00122412968946 | 0.01% |
16.0039 | 15.992 | 0.011900000000001 | 0.07% | 16.0046691224682 | -0.00076912246821 | 0.00% |
17.0031 | 16.992 | 0.011099999999999 | 0.07% | 17.0036641849617 | -0.000564184961664 | 0.00% |
18.0079 | 17.996 | 0.011900000000001 | 0.07% | 18.0066536152993 | 0.00124638470065 | 0.01% |
19.0098 | 19 | 0.009799999999998 | 0.05% | 19.0096459622891 | 0.000154037710868 | 0.00% |
20.0035 | 19.996 | 0.0075 | 0.04% | 20.0046465563641 | -0.001146556364134 | -0.01% |
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