Voltage Regulator - 5V

Discussion in 'The Projects Forum' started by daneloctober, Feb 11, 2013.

  1. daneloctober

    Thread Starter New Member

    Mar 22, 2012

    I'm at my wit's end trying to find a good solution for a simple problem... I need a regulator that accepts about 12 - 24V input and outputs 5V, and at least 2A of current.

    I know I can get a linear regulator, but I have size constraints. The heatsink I'd need just won't fit. I'm thinking I could just use a switching regulator IC (step-down). I'm familiar with IC's that need an inductor, a cap, and a diode, but my friend said that there are some certain voltage step-down IC's that do not need any external components. Can anyone give me suggestions?... THANKS!!!
  2. takao21203

    AAC Fanatic!

    Apr 28, 2012
    These are available on the internet for very little money.

    Sometimes I make my own, but often it is not worth it.

    Buyincoins has these (for instance).

    Even a switcher needs cooling for 2 Amps.
    daneloctober likes this.
  3. t06afre

    AAC Fanatic!

    May 11, 2009
    daneloctober likes this.
  4. RamaD

    Senior Member

    Dec 4, 2009
    Upto 1.5A, OKI-78SR series regulators available at Digikey. These are almost drop-in switching regulator replacements for 78XX series.
    daneloctober likes this.
  5. daneloctober

    Thread Starter New Member

    Mar 22, 2012
    Wow, thanks for the replies!!!

    I think I'm going to go with the LM2596. I can't buy premade boards because the regulator has to be part of a bigger board.

    Now a follow up question. I don't think I'll be going beyond 2A. So, if the LM2596-5.0 has 80% efficiency, and I'll be drawing 2A max, will it always dissipate 2.5W??? I calculated that like this:

    output of 5V * 2A = 10W
    efficiency 0.8 so, 10W/0.8 = 12.5W of input needed for 10W.
    12.5W - 10W = 2.5W

    My question is, do i still need a heatsink for that?...