It’s on – TPS54061 switching regulator vs. LM317 linear regulator

Other Parts Discussed in Post: LM317, TPS54061

I have to admit my obsession with DC/DC converters…and kitchen utensils.  For some utensils on the market, the ingenuity and usefulness instilled by its designer are marvelous, and the product begs us for purchase.  While recently visiting the First Monday’s Trade Days in Canton, Texas, which boasts to be the world’s largest outdoor flea market, a unique kitchen utensil caught my eye that I had to have – a pineapple slicer.  It looks like a bigger version of an apple slicer, and easily removes the core and skin of the pineapple in one quick, downward motion. 

Pineapple slicer/corer

Comparison between slicer and knife

When I got it home, I was curious to see how well it worked compared to the good old-fashioned knife.  To begin the comparison, I bought two pineapples and conducted an experiment.  My wife used the knife, and I used our new pineapple slicer.  The slicer was definitely quicker and less messy, and the knife yielded slightly more useable fruit by allowing strategic slicing.

Similarly, comparing several power management solutions to determine which solution best solves the problem can be insightful.  However, time constraints may limit experimentation, especially with characteristics that seem obvious.  When the TPS54061, a 60V 200mA synchronous-buck converter with integrated MOSFETs released, it begged comparison to the venerable LM317, a very popular 3-terminal 40V linear regulator, for a typical industrial 24V input, 5V/100mA application.  At first glance, the differences between a linear regulator and a switching regulator seem obvious.  However, a detailed comparison benefits designers by quantifying the obvious, or clarifying the uncertain.  A quantitative comparison between the size, efficiency, thermal performance, transient response, noise, complexity, and cost of each solution puts the trade-offs of a simple power management design into perspective.

Heat generated from each circuit (white indicates highest temperature)

Heat generated from each circuit

Check out the article “Linear versus switching regulators in industrial applications with a 24V bus”, and you can be the judge whether the pineapple slicer or the knife is better for your application.  For those who like to design their own linear regulators from scratch, the TPS54061 and LM317 are compared alongside a discrete transistor and Zener diode regulator.  Let us know which works best for you.

For more power management solutions, visit the Power House blog.