# How to limit LM2596 output current

Joined Sep 10, 2017
23

How can Lm2596 constant output current be limited ?

How lm2596 cc cv module like in the picture control output current ?

#### dl324

Joined Mar 30, 2015
12,871
Do you understand that there's a difference between current limiting and constant current?

The module appears to have current limiting. That doesn't mean current will constant at any limit you set.

Joined Sep 10, 2017
23
Do you understand that there's a difference between current limiting and constant current?

The module appears to have current limiting. That doesn't mean current will constant at any limit you set.
No i dont really know the difference ?
What does you mean?

And why u think it is current limit not constant current ?

#### dl324

Joined Mar 30, 2015
12,871
No i dont really know the difference ?
For constant current, the current would be constant.

For current limiting the maximum current will be limited, but it can fall below that level. Google hiccup current limiting.

Joined Sep 10, 2017
23
For constant current, the current would be constant.

For current limiting the maximum current will be limited, but it can fall below that level. Google hiccup current limiting.
So i think current limit will be what i'm looking for.
How this module achive current limit for lm2596 ? Does it rely on variable resistor ?

#### dl324

Joined Mar 30, 2015
12,871
How this module achive current limit for lm2596 ?
Can't say. The IC doesn't appear to have built-in current limiting.
Does it rely on variable resistor ?
Obviously.

Joined Sep 10, 2017
23
Can't say. The IC doesn't appear to have built-in current limiting.
Obviously.
So u think all output current goes through that potentiometer ?
For 12v 2A is equal 24 watt , Do u think is this pot capble of handling it ?

#### dl324

Joined Mar 30, 2015
12,871
So u think all output current goes through that potentiometer ?
No. The obvious thing to do would be to use the pot to set a trip voltage for a voltage comparator. Since the regulator has a shutdown pin, that could be used to turn the regulator off during overcurrent conditions. That would make current limiting hiccup mode.

#### AlbertHall

Joined Jun 4, 2014
11,309
Or you could pull up the feedback voltage to reduce the output voltage when the current exceeds some set limit.