I'm having some odd behavior of my TPS73601 circuit and I wonder what could cause it.
Input voltage is 3.5 V. Enable pin is LOW. Feedback is set up for 2.5 V output.
There are other parts of my system, powered by other regulators, where signal lines might be leaking a small current back into the output of the TPS73601.
As far as I can locate in my design, all these cases should be through at least a couple kOhms of resistor.
Depending what order I power things up, I will often see 0.6 V at the output of the '73601, even though the enable pin is low.
If I apply a heavy load (1 ohm to ground) the output goes to 0, but returns to 0.6 V when the load is removed.
If I briefly take ENABLE high and then low again, output goes to 0.
Or, if I briefly disable some other supplies in my system, holding '73601's ENABLE low, the output goes to 0.
This happens whether the other supply is one of the ones that might be leaking into the 73601's output or not.
I guess maybe this is because toggling the other supplies on and off causes a ripple in the upstream supply.
Or maybe a ripple in the current leaking into the '73601 output.
Any ideas what could cause this and how to prevent it?
Thanks,
Matt
