Other Parts Discussed in Thread: LP38502-ADJ, TPS7A85A, TPS7A83A
I am looking at using a LP38513-ADJ or a LP38502-ADJ to provide a 4V supply from a 5V source, and I would like to try to use a feed forward capacitor to slow the inrush current on my design. For reasons that are out of my control I need to put 100uF of low ESR capacitance in my design. Unfortunately I’m concerned about the short rise time (therefore large input current) pulling down my 5V power supply.
I was wondering if using a larger feed forward capacitor would be a good way to limit this. In my simple breadboard test I’ve been able to increase the rise time to somewhere around 400us. I was wondering if this isn’t a horrible Idea, and what the best method is to ensure that the power supply is stable. Do I need to physically build the circuit and inject a small voltage into the feedback path, like you would to measure the open loop gain of a switching converter?