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I'm fairly new to electronics. Please explain briefly why/why not.

What I got from the datasheet:

  1. I can use SENSE AND/OR VDD.
  2. VDD threshold voltage is 3.05V

Now my questions:

  1. Could I leave SENSE unconnected if I would only want to use VDD or should I connect VDD and SENSE to the same wire?
  2. Would I have to use a voltage divider as in the diagram or could I just connect the power supply and it would it activate at 3.05V threshold?

Link to datasheet: TPS3805H33QDCKREP block diagram

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  • \$\begingroup\$ It looks at the voltage and pulls a pin high or low. I linked the datasheet which has a short description in case you've missed. \$\endgroup\$ – cjsd Dec 7 '17 at 3:01
  • \$\begingroup\$ i was checking if you may have the wrong idea about the chip. ... deleting my comment. \$\endgroup\$ – jsotola Dec 7 '17 at 3:02
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    \$\begingroup\$ the two halves are the same, except that the sense input uses an external voltage divider. .... if you bring sense to 0V then reset will activate. sense input needs to be above 1.226V or maybe higher because of the the hysteresis band. i think that if you leave it unconnected then you may experience spurious resets. \$\endgroup\$ – jsotola Dec 7 '17 at 3:08
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  1. For the TPS3805, you have to use both inputs. Tying sense to GND will always activate the reset. Leaving it unconnected will cause false resets due to noise.
  2. You can connect it to VDD, this will effectively disable the input.
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  • \$\begingroup\$ Part 2 is not really clear for me yet :/ \$\endgroup\$ – cjsd Dec 7 '17 at 13:53

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