MP3429 as POWER PATH Manager aka MP3429 pin 8 (Output) is forced when EN (pin 11) is LOW

DC-DC Power Converters
1

Good Morning/Afternoon MPS comunity.

I have a question.

Because of

  • lack of PCB space,
  • very strict current margin
    we are currently using MP3429 as a power path manager in place of a power switch (for example TPS2022D)

The output of MP3429 (pin 8) is shared with a TPS2022D; the output of TPS2022D force the output of MP3429 (pin 8) up to 5V (when Enable pin 11 is low, MP3429 disable)

Could this (on long term), damage MP3429? The product should last years.

Best regards and thanks for your time.

2

Hi sergio.pavesi,

Welcome to the MPS Technical Forum. To clarify, you’re using both the MP3429 and the TPS2022D in your design? I’m not sure I understand why you have a boost converter’s output connected to the output of a power switch which in turn is pulling the output rail of the boost to 5V. If you are able to clarify and/or share a circuit schematic please, that might helpful in order to answer your question. Thank you!

3

Hi Bryan,

thanks for your reply.

In the following there an image with the simplified circuit.

Best Regards

image
image1568×660 13.2 KB

4

Hi sergio.pavesi,

Thank you for your patience. As described, your design should operate fine without long term damage to the MP3429.

5

I would like to do something similar, but with the mEZD41503A-B.
Since the MP3429 enable pin is not accessible, what harm would there potentially be if I put 5V on the converter output and disconnect the 3.6V battery from the input of the module?
Thanks!