DC DC power supply

**modh1984** · 11-21-2005, 08:52 AM

Im looking for a DC DC power supply that:

Input: 12-30V
Output: 5V
Putput current: 150mA or more
Efficiency: 85-90%

I need it to be in a small package. If you know of any, please post. Thank you.

**modh1984** · 11-21-2005, 09:26 AM

I am acually looking for a switching regulator, so when the input ranges for 12-30V it should output 5V.

**pip** · 11-21-2005, 09:55 AM

http://www.mp3car.com/store/product_...roducts_id=138

**modh1984** · 11-21-2005, 01:48 PM

2 big and not quite what im looking for... im looking for something like this ( http://focus.ti.com/lit/ds/slts057b/slts057b.pdf ) but smaller and i dont need 1.5A of output current.. .. i need only 150mA

http://focus.ti.com/lit/ds/slts057b/slts057b.pdf

Thanks

**Bugbyte** · 11-21-2005, 05:28 PM

Radio Shack 7805 5volt regulator.

**modh1984** · 11-22-2005, 01:41 PM

I found what I was looking for, thanks for your help.

http://cache.national.com/ds/LM/LM2671.pdf

**Wiredwrx** · 11-22-2005, 02:29 PM

Originally Posted by modh1984

I found what I was looking for, thanks for your help.

http://cache.national.com/ds/LM/LM2671.pdf

Overkill, and to much external components.

Try a 7805 as mentioned earlier. Needs 2 caps and your done.

Michael

**andrewb** · 11-23-2005, 02:01 AM

>Try a 7805 as mentioned earlier. Needs 2 caps and your done.

That's an LDO. Might get hot, but not too much at 50-100mA.
Not high efficiency. Rather more like 40% efficiency.

-Andrei

Originally Posted by Wiredwrx

Overkill, and to much external components.

Try a 7805 as mentioned earlier. Needs 2 caps and your done.

Michael

**Wiredwrx** · 11-23-2005, 12:18 PM

Originally Posted by andrewb

>Try a 7805 as mentioned earlier. Needs 2 caps and your done.

That's an LDO. Might get hot, but not too much at 50-100mA.
Not high efficiency. Rather more like 40% efficiency.

-Andrei

I agree it isn't very efficient, though I am not sure why that matters to the OP. As for heat, at 100ma that really shouldn't be an issue. If it is, he can always use something like an LM338, which at 100ma probably won't even notice the heat.

Michael