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Propeller /RES pin — Parallax Forums

Propeller /RES pin

David BetzDavid Betz Posts: 14,519
in Propeller 1
Does the /RES pin on the Propeller have an internal pull-up resistor?

Comments

  • Tracy AllenTracy Allen Posts: 6,667
    edited 2017-03-04 20:39
    Yes, it is around 5kΩ pullup to Vdd.

    And no, a subtle distinction. The internal 5kΩ is not tied directly to Vdd, rather, it is tied to the output of the brownout detector, so when BOE is tied low (enabled) and a brownout occurs, the 5kΩ at that time becomes a pulldown to Vss. Here is a reference experiment.
    http://forums.parallax.com/discussion/comment/1186806#Comment_1186806
    The upshot is that it is unnecessary and generally a bad idea to add an external pullup to the /res pin.
  • David BetzDavid Betz Posts: 14,519
    That explains why I see 3.3v on /RES even though nothing is connected to it. Thanks!
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