I'm using ADS1015 in one of my development.I have configured for 2.048 volt reference with single ended analog input. As per design we are dropping the 4-20mA current from a pressure transmitter across a 220 ohm resistor. I have given this current in column E in the following table. Actual voltage we got at the ADC input is in the column F. Column G is the expected ADC count for the respective voltage in the column F. But we are getting the getting ADC count as per column H. In the attachment you can see that there is no variation even when the ADC input voltage is varied.We have checked this with different reference voltage setting (4.096, 6.192). We are getting same kind of missing codes.
Can somebody share your inputs to overcome this issue?
| E | F | G | H |
| mA | volts | Exp.Counts | Actual Counts |
| 4 | 0.92 | 920 | 921 |
| 4.01 | 0.9223 | 922 | 927 |
| 4.02 | 0.9246 | 925 | 928 |
| 4.03 | 0.9269 | 927 | 928 |
| 4.04 | 0.9292 | 929 | 928 |
| 4.05 | 0.9315 | 932 | 928 |
| 4.06 | 0.9338 | 934 | 928 |
| 4.07 | 0.9361 | 936 | 930 |
| 4.08 | 0.9384 | 938 | 935 |
| 4.09 | 0.9407 | 941 | 942 |
| 4.1 | 0.943 | 943 | 947 |
| 4.11 | 0.9453 | 945 | 949 |
| 4.12 | 0.9476 | 948 | 949 |
| 4.13 | 0.9499 | 950 | 949 |
| 4.14 | 0.9522 | 952 | 949 |
| 4.15 | 0.9545 | 955 | 949 |
| 4.16 | 0.9568 | 957 | 949 |
| 4.17 | 0.9591 | 959 | 955 |
| 4.18 | 0.9614 | 961 | 961 |
| 4.19 | 0.9637 | 964 | 965 |
| 4.2 | 0.966 | 966 | 969 |
| 4.21 | 0.9683 | 968 | 969 |
| 4.22 | 0.9706 | 971 | 969 |
| 4.23 | 0.9729 | 973 | 969 |
| 4.24 | 0.9752 | 975 | 969 |
| 4.25 | 0.9775 | 977 | 969 |
| 4.26 | 0.9798 | 980 | 974 |
| 4.27 | 0.9821 | 982 | 980 |
| 4.28 | 0.9844 | 984 | 985 |
| 4.29 | 0.9867 | 987 | 989 |
| 4.3 | 0.989 | 989 | 989 |
| 4.31 | 0.9913 | 991 | 989 |
| 4.32 | 0.9936 | 994 | 989 |
| 4.33 | 0.9959 | 996 | 989 |
| 4.34 | 0.9982 | 998 | 989 |
| 4.35 | 1.0005 | 1001 | 993 |
| 4.36 | 1.0028 | 1003 | 999 |
| 4.37 | 1.0051 | 1005 | 1003 |
| 4.38 | 1.0074 | 1007 | 1009 |
| 4.39 | 1.0097 | 1010 | 1009 |
| 4.4 | 1.012 | 1012 | 1009 |
| 4.41 | 1.0143 | 1014 | 1009 |
| 4.42 | 1.0166 | 1017 | 1009 |
| 4.43 | 1.0189 | 1019 | 1009 |
| 4.44 | 1.0212 | 1021 | 1014 |
| 4.45 | 1.0235 | 1024 | 1019 |
| 4.46 | 1.0258 | 1026 | 1023 |
| 4.47 | 1.0281 | 1028 | 1029 |
| 4.48 | 1.0304 | 1030 | 1029 |
| 4.49 | 1.0327 | 1033 | 1029 |
| 4.5 | 1.035 | 1035 | 1029 |
| 4.51 | 1.0373 | 1037 | 1029 |
| 4.52 | 1.0396 | 1040 | 1029 |
| 4.53 | 1.0419 | 1042 | 1031 |
| 4.54 | 1.0442 | 1044 | 1037 |
| 4.55 | 1.0465 | 1047 | 1042 |
| 4.56 | 1.0488 | 1049 | 1048 |
| 4.57 | 1.0511 | 1051 | 1050 |
| 4.58 | 1.0534 | 1053 | 1050 |
| 4.59 | 1.0557 | 1056 | 1050 |
| 4.6 | 1.058 | 1058 | 1050 |
| 4.61 | 1.0603 | 1060 | 1050 |
| 4.62 | 1.0626 | 1063 | 1050 |
| 4.63 | 1.0649 | 1065 | 1056 |
| 4.64 | 1.0672 | 1067 | 1063 |
| 4.65 | 1.0695 | 1070 | 1068 |
| 4.66 | 1.0718 | 1072 | 1070 |
Regards,
Kalimuthu C
