PCB heat up

[Mahsheed]

Thank you very much sir. I found LM2596S and that is working perfectly fine for this.

[Paul van Avesaath]

Hi robertferanec,
I have studied the LMZ23603TZX and that is exactly what I need for my design. But I have a problem. It costs 8.8 USD/PSC. So, can you please suggest me some other substitute (similar to LMZ23603TZX) whose cost is low?

you could try and ask for samples

[robertferanec]

Normally I would just go for example to TI website and search for the chip I need. For example like this: http://www.ti.com/power-management/n.../products.html

[Mahsheed]

Hi robertferanec,
I have studied the LMZ23603TZX and that is exactly what I need for my design. But I have a problem. It costs 8.8 USD/PSC. So, can you please suggest me some other substitute (similar to LMZ23603TZX) whose cost is low?

[Mahsheed]

Okay. Thank you very much. Let me have a look at that. If I find any issue, I will ask here again :P

[robertferanec]

Does that mean the Heat sink pad on PCB wont do in case of SMD and only through hole with good heat sink would do the work. Right?

- yes, but this it not the point. The important point is, that all the heat is wasted energy which you can safe by using a switching power supply regulator.

[Paul van Avesaath]

have a look at somtething like this

http://www.ti.com/product/LMZ23603

just as easy as an LDO

also take into account your car battery is 12V but when the car is running it is being charged at +/- 14.4 V.. so your input voltage is higher..

[Mahsheed]

I dont think you can take this away just with PCB

Does that mean the Heat sink pad on PCB wont do in case of SMD and only through hole with good heat sink would do the work. Right?

[Mahsheed]

Are you suggesting Buck converter?

[robertferanec]

1A continuous current * 7V difference between Input and output = 7W power (7W of heat on the regulator)

You will need a good heatsink on the regulator to take away 7W (I dont think you can take this away just with PCB). As Paul van Avesaath and Lakshmi suggested, I would go for a switching power supply. Linear regulators are not good when used in applications where input - output voltage and output currents are high.

PS: Especially, when you are creating battery powered application, the 7W is wasted power - you will be discharging battery without actually using half of the energy.

[Mahsheed]

Can you please explain? I mean I could not understand switchmode power supplies.

[Paul van Avesaath]

then change over to another type of powe supply.. there are plenty of switchmode power supplies that will do what you want. these will not heat up your pcb

[Mahsheed]

this way the heat can dissipate in the plane and thus it will heat up your PCB.

But I want my pcb not to be heated up

[Paul van Avesaath]

your generating heat because of the drop in voltage.. the 7805 is dissipating that 6Volts stepping down from 12V.
regarding your question you can go to SMD, but you have the ensure there is a large GND plane connected with a lot of via's (preferrably multiple planes on different layers)
this way the heat can dissipate in the plane and thus it will heat up your PCB. either way some airflow would be recommended.

a switching regualtor would be better in this case..

[Mahsheed]

Ok, Waiting for his reply