I tried out the STBB1 with the evalboard to drive a load of 500mA.
My trials were successfull. I did them by switching on my power supply with 5V and afterwards I was switching the 500mA Load on and off at the output. -> everything cool.
Now I have my final design on the table and I found out, that when I power on my supply it is going into current limit.
I could find the difference to my trials with the evalboard:
-> In the final design, the load is already in place when the power supply is switched on.
When I set a current limit of 1A, then the output voltage will not be generated and the current is causing problems within the STBB1.
I killed tow of the devices and my Evalboard during figuring out the problem.
So how to overcome these kind of problem? The STBB1 says it has a soft start, but this doesn't seem to do the job.
The overall design is like this:
There is a 5V source with a long cheap cable to my device. I wanted to overcome the voltage drops caused by the cable with the buck/boost converter to supply my resistive load of 300mA with a constant voltage of 5V.
So my problem is, that this will not work when the starting of the DCDC needs such high peak currents, because the resistance of the wires is preventing this.
In the end I created a more complex problem without solving the original one :(
Does anyone have experiences with powering up the STBB1 and its Softstart here?
best wishes,
Stefan
