Switching Voltage Regulator question
Posted: Sat Sep 04, 2010 5:56 am
I'm trying to figure out which parts I need to make a switching +5V voltage regulator. Up to this point, I've always used an LM7805 linear regulator, which works great at low currents. But the current draw on my latest project is around 0.8A. The LM7805 generates too much heat in this situation, and can't consistently maintain +5V without active cooling. So I'm looking at building a switching regulator around an LM2575.
The schematic for the LM2575T-5 lists 4 external components: 2 caps, 1 inductor, and 1 diode. The caps are easy, but I'm not sure about the other two parts. What kind of inductor and diode do I need to get? When I look for inductors, I find everything from ferrite beads, to RF chokes, to toroid inductors. Which of these does a switching regulator work with? For the diode, does it need to be anything special? Zener, schottky, etc?
The schematic for the LM2575T-5 lists 4 external components: 2 caps, 1 inductor, and 1 diode. The caps are easy, but I'm not sure about the other two parts. What kind of inductor and diode do I need to get? When I look for inductors, I find everything from ferrite beads, to RF chokes, to toroid inductors. Which of these does a switching regulator work with? For the diode, does it need to be anything special? Zener, schottky, etc?