I am powering my board with a TPS63030 driven by a battery at its input. I want to be able to switch in a shunt. When I enable the shunt, I'll drive EN low to disable the TPS63030. This disconnects the output from the load. I don't know how fast, but I'm guessing I can switch in my shunt at the same time as I drive EN low an be just fine.
When I switch out the load and enable the TPS63030 may be more complicated. There is info about the part softstarts going from Vout = 0, but I'm unclear on how it will respond to being enabled with Vout > 0. I suspect if 0 < Vout < Setpoint, it will simply ramp up to the setpoint following the same curve as if it had started from 0. But what happens if it's enabled at a point when Vout > Setpoint. Will it turn off the switching transistor until Vout falls?
This condition will not last long on my board. But it's possible for there to be 3V on the battery at a point when the switcher, set for 2.5V is enabled. My board always draws at least a few uA or more. The amount of decoupling on the supply is not excessive. So it will fall to 2.5V quickly if the transistor doesn't switch. But is that how TPS63030 behaves? Am I putting any stress on the part by doing this? Will I confuse the feedback loop and cause the output to undershoot significantly before it starts switching?
I appreciate any help.
