Categories

App note: External current limiting circuit

Posted on Saturday, May 5th, 2012 in app notes by DP

Learn how to implement fixed current limiting in power-supply designs:

In every power supply application there exists the possibility to short the output to ground causing excessive current to be drawn from the power supply. In order to limit the output current from becoming excessive the following examples of current limiting circuits are suggested.

This entry was posted on Saturday, May 5th, 2012 at 11:00 pm and is filed under app notes. You can follow any responses to this entry through the RSS 2.0 feed. You can skip to the end and leave a response. Pinging is currently not allowed.

2 Responses to “App note: External current limiting circuit”

  1. Michael Taylor says:

    I would note that the techniques described only limit current to the maximum allowed current limit rather than reduce the current at the pass transistor (top left in above diagram) in the case of a fault condition. So I wouldn’t recommend it for moderate to high current applications (say above 3 to 5A).

    EDN Design Idea Circuit adds current-foldback protection (EDN July 21, 2005) outlines a common current fold-back design, used to reduce the current in the case of excess current draw, as often associated with component or circuit failure, e.g. a short-circuit in the power supply’s load.

    Thanks for the great blog.

  2. hernan says:

    my input 12v 500ma, I want at the output 12v 400ma….how to??

Leave a Reply

Notify me of followup comments via e-mail. You can also subscribe without commenting.

Recent Comments

  • KH: TPS62200 will get him to under 15uA, a bit better than the 20-30uA he mentioned. I would try the same thing. Switch some resistors in...
  • KH: Yeah, it's an end-user thing. Very few people would spend hundreds of hours on this kind of project and sustain it. It's more or less...
  • Max: Not quite a dinosaur if you've seen Big Hero 6 though... wait. You've watched it with your kids, didn't you? That's cheating...! ;) One of...
  • Edward Mallon: A visiting researcher dropped by our humble basement workshop with questions about the physical skill level students would need if they added one of our...
  • KH: And that looks really expensive... Only browsed the vid though, I'm an dinosaur so I had the sound off too. Nice of him to open-source...