Other Parts Discussed in Thread: TPS2595
Hello,
According to "Figure 20. Accuracy vs Overload Current Limit" on page 10 of the datasheet the accuracy of the E-fuse varies strongly over the current limit span. In a simple estimation I receive following spread:
|
Min lim [A] |
Target [A] |
Max lim [A] |
|
0,70787 |
1 |
1,29387 |
|
0,80008 |
1,1 |
1,40208 |
|
0,8843 |
1,2 |
1,5183 |
|
0,9705 |
1,3 |
1,6325 |
|
1,07261 |
1,4 |
1,73061 |
|
1,16376 |
1,5 |
1,83976 |
|
1,2728 |
1,6 |
1,9308 |
|
1,3858 |
1,7 |
2,0178 |
|
1,48487 |
1,8 |
2,11887 |
|
1,58592 |
1,9 |
2,21792 |
|
1,68895 |
2 |
2,31495 |
|
1,79396 |
2,1 |
2,40996 |
|
1,90095 |
2,2 |
2,50295 |
|
1,98708 |
2,3 |
2,61708 |
Is the accuracy really this poor? During the limited testing I have done the E-fuse almost always limits the current to more-or-less exactly the value set by "R-lim" resistor. What factors affect the precision most: temperature/voltage/process?
What I'm looking to do is to set a relatively precise current limit using TPS259271.
Best Regards,
Dmitri
