DC/DC short circuit detection

Status
Not open for further replies.
S

shaiko

Advanced Member level 5
Joined
Aug 20, 2011
Messages
2,644
Helped
303
Reputation
608
Reaction score
297
Trophy points
1,363
Visit site
Activity points
18,302
What is the common method for a DC/DC converter to detect a short circuit on the output?
Does it simply assume a short circuit because of overcurrent ? Or there're other ways?
 

Most of the converters will have both over current protection and short circuit protection mechanisms....see the actual datasheet for details. generally short circuit will be associated with output voltage reduction in addition to Over currentt....
 
Reactions: shaiko

    S

    shaiko

    Points: 2
    Helpful Answer Positive Rating
Most of the converters will have both over current protection and short circuit protection
Click to expand...

How is short circuit protection implemented if not via means of detecting current flow over a certain threshold ?
 

You can detect a short circuit by direct current sense
(against a threshold that sits above max normal current
limit, and perhaps in concert with an output undervoltage
term, plus some idea about whether the part is in soft start).

You can check for failure-to-transition, on a switching
output. But this is not useful at the DC output of the
brick.

A key question is short-to-what? Most people think about
ground. There are other possibilities. But dealing with every
single stinkin' permutation of monkey screwdriver stupidity
will blow your design schedule right out of the water.
 
Reactions: shaiko

    S

    shaiko

    Points: 2
    Helpful Answer Positive Rating
The IC you have chosen has the capabiltiy for current limiting
Click to expand...
I know that...but does it also have a mechanism for short circuit detection?
If it does, how does it work?
 

Review the "Overcurrent Protection and Frequency Shift" section in the TPS54140A datasheet and decide if it offers sufficient protection for your application.
 
Reactions: shaiko

    S

    shaiko

    Points: 2
    Helpful Answer Positive Rating
No it does not detect a short cct, you need to define how hard a short, 0.1V, 0.2V, 0.005V...?
if you need to detect a short you will need to devise your own ckt.
 
Reactions: shaiko

    S

    shaiko

    Points: 2
    Helpful Answer Positive Rating
Status
Not open for further replies.

Similar threads

Menu
Log in
Register
Cookies are required to use this site. You must accept them to continue using the site. Learn more…