[SOLVED] input current for lm2576

[electronion]

I need information please..
How is the max current input of lm2576 from unregulated power supply? if I use 5A transformer is it ok?

 

[karthickb3e]

it is not a load ..........
it only passes current to the load connected to it...
only worry about max output current........(that depends on load)

 

[electronion]

thank you karthickb3e,
I plan to build a power supply with it..
lm2576 has 3A max. output right? so I want to increase it to max.5A with some transistor circuit. so, I need 5A transformer..
about the max output current, why it could depends on load? how?

 

[karthickb3e]

i cant clear with your question? i think lm2576 is a regulator.. why you try to make it to 5Amps using external circuit...
is it your circuit need 5A current.....?
if necessary try to find other regulator of 5Amps driving capacity!.......
what is your application for this circuit?.......

 

[Raza]

What is your required voltage range?
For 5 amperes you can use LM350 directly for 5 you can use two regulators in Parallel.

 

[electronion]

I want to build a DC power supply with it..
in datasheet, LM2576 has 12 volt max output voltage and 3 A max out current..
I just want to try boost up the max out current to 5 A.. it means I have to use 5A transformer in its input..
now, I just want to know about the input current of LM2576 coz the datasheet doesn't explain about the current input, it just explain about the voltage input of LM2576...
if I use 5 A input from transformer to lm2576. is it not broken?

thanks

 

[karthickb3e]

no it not broken.....
it broken when if u connect load which takes more than 3A current..
what about your load specfications

 

[Raza]

electronion,
Co current is consumed by LM2576 at its own even if you use 10 ampere transformer. The current is always LOAD DEPENDENT. If you do not connect any load to the REGULATOR (lm2576) nothing will happen to LM2576. But it will damage if you draw more current than 3 ampere (the rated current for LM2576). If still not clear please put your question with more elaboration.

 

[alexan_e]

But it will damage if you draw more current than 3 ampere (the rated current for LM2576).

The regulator has thermal and over current protection so it will not be damaged

The output switch includes cycle-by-cycle current limiting, as well as thermal shutdown for full protection under fault conditions.

Alex