I am using two units in my design of the DC/DC step-down converter LTM8029 (link) to generate two different voltages. The first one is -5V and the second one is 4.5V. The way that the IC is connected on each of them is as shown below...
The only difference from my design is that both RUN pins are connected to an external controller to switch them on and off as needed.
The issue is the following: I can switch on and off the regulator with positive output through the RUN pin, but not in the case of the regulator with -5V output. It stays in a kind of latch condition which I can't get to understand...
I have two boards (each of them mounts both regulators), and in both I am having the same issue.
But more surprisingly, I have decided to run some simulations on LTSpice and I can see the same issue there. Any ideas as to why this may be happening?
Many thanks in advance!
[edited by: rhdp1 at 8:45 PM (GMT -4) on 28 Apr 2022]