What is the meaning of "Long time maximum output current ≥ 1.5 A"?

[Wrichik Basu]

I am looking at the module HLK-5M05, which is a $5\ V, \ 5\ W$ AC-DC power supply module. The advantage of this module is that, it does the stepping down and rectification within itself, and is a switching source, so fluctuations in the voltage grid won't affect the output (at least that's what is advertised).

I was looking at the data sheet of this module (attached). If you jump to page 2, under product model, it says the output current is $1000\ mA$.

Now, look at the output characteristics of 5V/1000mA in page 6. It says,

Short time maximum output current	$\ge \ 1200\ mA$
Long time maximum output current	$\ge \ 1000\ mA$

How can the maximum output current be greater than some value? Does this mean that I can draw more than $1\ A$ from this module? Doesn't seem so. Then what are they trying to say?

 

[phinds]

I think what they must mean is that the short term max current is AT LEAST 1200ma and the long term is AT LEAST 1000ma. So, they are saying that, for example, you might have a long term max current of 1050ma but you can't count on it, you can only count on 1000 for a generic chip.

 

[Wrichik Basu]

but you can't count on it, you can only count on 1000 for a generic chip.

Didn't understand this part.

 

[phinds]

Didn't understand this part.

What I mean is exactly what I said ... if you buy one of those chips, you MIGHT get one that could sustain a long term current of 1050ma, but you can't count on it, you can only count on it being able to sustain a long term current of 1000ma (so you should never design one of those chips into a circuit that has to sustain a long term current of more than 1000ma). Also, you CAN count on it being 1000ma, you don't have to worry about it only being able to sustain 990ma, for example.

 

[Joshy]

My interpretation is it's like a safe operating area (SOA) I normally see on transistors, and so maybe they just used words to describe it instead? So maybe the maximum output current they advertise is for maximum DC where their short time one can handle a pulse or brief moment of (over) current.

 

[DaveE]

One of the problems with sourcing from one of the many low-cost PS suppliers is that they don't spend money on Application Engineers and they don't document their products as well as we all would like. This practice ends up pervading the rest of the PS industry because they have to compete.

For comparison (probably a waste of your time), here's an op-amp data sheet from long ago:
LM324 datasheet

BTW, I agree with everyone else. Regardless of the syntax, what they are saying is you can use this up to 1A forever, and 1.2A briefly. Briefly usually would refer to how long it takes to get too hot.