I am having some trouble getting the TPS26631 to perform as expected.
I am using the device as input protection for a device and have the following requirements:
reverse polarity preotection, uvlo (9V), ovlo (30V), overcurrent protection (3.8A, latch-off).
Furthermore I have the PGOOD configured to trigger at 8.5V and tied to the enable of the SMPS.
I am using the demoboard to prototype this (with 600mA current limit).
However, I am running into the following issue.
When the load reaches 600mA, the output voltage of the TPS26631 starts to drop, when it reaches 8V, the PGOOD goes low.
This in turn causes the SMPS to switch off and the load to disappear, the TPS recovers and the whole thing starts again.
This causes the output of the TPS26631 to go into a hiccup mode instead of latching off.
Yellow: Input Voltage
Blue: Output Voltage
Green: Output Current
Red: PGOOD
What should I change in order to fix this?
