I am observing too much current draw in a TPS389033 supervisor on several boards. I am measuring about 9mA, which is enough to affect the supply being monitored. I am powering it through the TPS70933 LDO below. A diode is placed in the path of the LDO in order to provide added protection against the microcontroller trying to charge a backup battery. At the supervisor's and microcontroller's expected power draw of 250uA the voltage drop here should negligible, well under 100mV. And on most of my boards, indeed it is. (I am willing to remove this diode but it does not fix my current draw problem.)
On some boards I see closer to 2.8V at the TPS389033 VDD and SENSE pins, due to the voltage drop induced by 9mA current. I indicated the points where I observed this low voltage below. These boards are held in reset, as this is below the 3.189V VITP threshold.
Strangely, on these same boards, I measure 4ohms between the CT pin and VDD. On other boards, I do not see this, and do not see the same droop in my backup power rail. I have reflowed the part and do not think it is a solder issue. What else can I look at to try to identify why these parts are pulling my backup power supply down?