Tool/software:
Hi team,
We occur TI INA423X GUI tool will configure wrong number in calibration parameter with max expected current 3A, so I calculate the right number and fill in (5107).
After that, I read the Current register to calculate the real current as below Table1.
As you see, the error will rise quickly under 5mA, even I read power for a while to calculate average current.
1mA/5mA measurement
|
Power value |
Power(W) |
BUS value |
BUS volt |
Current |
Enegy value |
Energy(J) |
E=>Watt |
E=>Current |
|
2 |
0.0058594 |
2623 |
4.1968 |
0.001396 |
7272 |
21.30469 |
0.005918 |
0.00141011 |
|
8 |
0.0234375 |
2623 |
4.1968 |
0.005585 |
13736 |
40.24219 |
0.022357 |
0.0053271 |
Table1
|
CH1:10m ohm |
VBUS:4.2V |
||||||
|
Current Load |
R_SHNT |
max expect current |
Current _LSB |
SHNT_CAL |
Current_REG |
measured current |
error(%) |
|
3 |
0.01095 |
3 |
9.15527E-05 |
5107.219482 |
32,767 |
2.999908447 |
0.00 |
|
2 |
0.01095 |
3 |
9.15527E-05 |
5107.219482 |
21829 |
1.998504639 |
0.07 |
|
1 |
0.01095 |
3 |
9.15527E-05 |
5107.219482 |
10912 |
0.999023438 |
0.10 |
|
0.8 |
0.01095 |
3 |
9.15527E-05 |
5107.219482 |
8728 |
0.799072266 |
0.12 |
|
0.7 |
0.01095 |
3 |
9.15527E-05 |
5107.219482 |
7636 |
0.69909668 |
0.13 |
|
0.6 |
0.01095 |
3 |
9.15527E-05 |
5107.219482 |
6546 |
0.599304199 |
0.12 |
|
0.5 |
0.01095 |
3 |
9.15527E-05 |
5107.219482 |
5451 |
0.499053955 |
0.19 |
|
0.4 |
0.01095 |
3 |
9.15527E-05 |
5107.219482 |
4361 |
0.399261475 |
0.18 |
|
0.3 |
0.01095 |
3 |
9.15527E-05 |
5107.219482 |
3272 |
0.299560547 |
0.15 |
|
0.2 |
0.01095 |
3 |
9.15527E-05 |
5107.219482 |
2182 |
0.199768066 |
0.12 |
|
0.1 |
0.01095 |
3 |
9.15527E-05 |
5107.219482 |
1092 |
0.099975586 |
0.02 |
|
0.08 |
0.01095 |
3 |
9.15527E-05 |
5107.219482 |
875 |
0.080108643 |
-0.14 |
|
0.06 |
0.01095 |
3 |
9.15527E-05 |
5107.219482 |
658 |
0.060241699 |
-0.40 |
|
0.04 |
0.01095 |
3 |
9.15527E-05 |
5107.219482 |
439 |
0.04019165 |
-0.48 |
|
0.02 |
0.01095 |
3 |
9.15527E-05 |
5107.219482 |
222 |
0.020324707 |
-1.62 |
|
0.01 |
0.01095 |
3 |
9.15527E-05 |
5107.219482 |
110 |
0.010070801 |
-0.71 |
|
0.005 |
0.01095 |
3 |
9.15527E-05 |
5107.219482 |
55 |
0.0050354 |
-0.71 |
|
0.003 |
0.01095 |
3 |
9.15527E-05 |
5107.219482 |
35 |
0.003204346 |
-6.81 |
|
0.001 |
0.01095 |
3 |
9.15527E-05 |
5107.219482 |
12 |
0.001098633 |
-9.86 |
Thanks!
Jeff
