Hello,
I have an application which requires a wide varying supply voltage and chose the PTN04050C to meet the requirements of the design. The part functions well in application, however, when "disabled", I cannot get the output voltage to settle to GND. It is important to the application that the supply be entirely removed to the load when disabled.
The design uses a high side load switch (U34) to pass 5V input to the module. When the load switch is disabled (measuring 0V at output/PTN04050 input), I am observing an output voltage of 2.4-3V regardless. I understand the portion of the datasheet outlining the limitations of the boost topology, but I don't quite understand what is supplying any energy to the PWM controller in the module in the absence of the input voltage.
In order to disconnect my load from the persistent output voltage, I figured I'll put another load switch after the pi filter, which adheres to the same logic as U34 in the below schematic. However, I fear that this fails to address what could be an existing issue in the design. Should I be able to "turn off" the module? Why is the output hanging at ~2.4V? Partial schematic below:
Is there some other way to realize 0V at the output of the PTN04050?
Thank you in advance for any guidance
