Tool/software:
Hi,
I am using the TPS26631 in a design and I set I_LIM to 2.52A (18 / 7.15kOhm) and my Cdv_dt is 100nF. I found that I can have 2.52A of current flowing through the eFuse continuously without a fault if I gradually increase the current draw. However, the issue arises when I enable the eFuse (through the SHDN pin) when there is already a load on the output. When enabled, the same current draw will cause the eFuse to start regulating and stay in auto-retry mode indefinitely.
When scoping the IMON line, if the load wasn't too large, I measured that the input current on startup would overshoot to a maximum of ~2.4A (making me think that the eFuse was regulating to 2.4A) and then settle lower to ~2.2A and there wouldn't be a fault. However if the load was increased such that the current never settled below ~2.4A, then a fault would occur and the eFuse would auto-retry indefinitely.
I understand that there will be some inrush current at startup, but what I don't understand is why the eFuse will fault on startup if the current is >2.4A but I can get it to reach 2.5A if I slowly increase the load after startup. Does the eFuse have a lower current limit on startup?
Cheers,
Cameron
