I love Pololu products and like to use them in all my projects.
I’m curious about something: What are the benefits of a Pololu voltage regulator board like the 5v, 1A Step-Down (D24V10F5)? I see it has a IC, and various resistors and other components, so I assume it has a level of sophistication. https://www.pololu.com/product/2831
How is it different from a simple L7805-style voltage regulator?
I’m not asking about the current capacity, obvious packaging/pin differences, the breadboard friendliness, or even SNDN and PG features. I can see those differences/benefits.
If I put those differences aside, does the Pololu provide better power or regulate the voltage in a different way?
I also don’t care about cost in the context of this question. I just want to understand what the Pololu Voltage Regulator board provides versus L7805-style package. Or do they do they same job in the same so it just comes down to the packaging preference, SNDN, and PG features?
I am designing custom PCBs for my robotic projects. Up to this time, I’ve been using Pololu voltage regulators, but sometimes I wonder to myself about these L7805-style items and how they differ.
Always trying to learn.
The main difference between the regulators we sell and 7805 type is the way they regulate the voltage. Power is always conserved, so when converting one voltage to another you have to account for the excess power (i.e. for a step-down regulator Vin * Iin = Vout * Iout + Pexcess) The 7805 is a linear regulator, so its input current is the same as its output current, and it reduces the input voltage by converting the extra power into heat. Our regulators are switching regulators, so instead, they use a control circuitry that turns them on and off and store energy in inductors and capacitors as needed to keep a steady output voltage. This means the average input voltage and current in are reduced and the input power is near the level of the output power. Essentially switching regulators turn on long enough to charge up the inductors and capacitors and for the output to reach the desired voltage and then turn off and let the inductors and capacitors feed their stored energy to the output until the voltage drops too low. This means they have much greater efficiencies and generally they can be made smaller while still handling more current.
The wikipedia article on switched mode power supplies is pretty good and has a section on the advantages and disadvantages of switching regulators and a linear vs switching comparison chart.
One final thing to note is that since linear regulators work by dissipating excess power, they can only reduce the input voltage. With switching regulators is it possible to step the voltage either up or down.
Got it. Thank you. That’s what I needed to know.