We have a board populated with the TPS2456 at the power input and we have noticed an undesired behavior when both inputs are populated with PSUs that we are hoping we can get resolved or at least work around. Essentially, the issue is that when we have both PSUs populated and then remove one, the input associated with the removed one seems to stay active. This also appears to be reinforced by the fact that the LED indicator on the board for this rail (on INx pin through a resistor) stays active and both the GAT1x and GAT2x pins remain at their active level.
Once a power input is removed, we can get the LED to reflect its absence properly by either pulsing the ENx (or ORENx instead works as well) pin or simulating a brief input short on the depopulated input (the LED will continue to reflect the proper absence of the input after these events). After these actions, the GAT1x and GAT2x pins will be at their inactive so it appears that by resetting the input, the TPS2456 is able to detect that there is now no power input. The supporting circuit for the TPS2456 in our design follows the layout in Figure 1, Two Sources, One Load Application, of the datasheet with the LEDs coming off of the INx nets through resistors as mentioned.
We would like to have the LEDs indicate that a power input has been removed--Is there something that we did wrong in our design or is this intended behavior? Thanks in advance for taking the time to look into this.
