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Project Notes

#153 AMS1117 Regulator

Test an AMS1117 3.3V linear regulator

The Build


The AMD1117 is a low drop fixed and adjustable voltage regulator from Advanced Monolithic Systems (AMS). It is similar to “1117” regulators available from a number of manufacturers including UTC and ST. Parts are available for a range of output voltages, including: 1.5V, 1.8V, 2.5V, 2.85V, 3.3V, and 5.0V.

The component I have (obtained from a seller on aliexpress) is marked: AMS1117-3.3 H1518 in a SOT-223 package.

As given in the datasheet:

  • dropout voltage (Vin - Vout): 1.1V typical, 1.3V max
  • Vin max: 15V
  • current limit: 1.1A typical, 1.5A max
  • pin out (from left front): ground, Vout, Vin

Circuit recommendations:

  • 22µF tantalum output capacitor

Some DMM measurements, with a 10kΩ output load:

Vin Iin Vout Iout Pin:Pout
5.09V 2.68mA 3.29V 333µA 13.64mW : 1.1mW

The inefficiency of a linear regulator is clear to see - we’re dissipating 12.74mW in the 1117, far more power than is actually delivered to the load. But they’re convenient!


NB: these diagrams use the custom AMS1117 module fritzing part


The Schematic

Credits and References

Project Source on GitHub Project Gallery Return to the LEAP Catalog

This page is a web-friendly rendering of my project notes shared in the LEAP GitHub repository.

LEAP is just my personal collection of projects. Two main themes have emerged in recent years, sometimes combined:

  • electronics - usually involving an Arduino or other microprocessor in one way or another. Some are full-blown projects, while many are trivial breadboard experiments, intended to learn and explore something interesting
  • scale modelling - I caught the bug after deciding to build a Harrier during covid to demonstrate an electronic jet engine simulation. Let the fun begin..
To be honest, I haven't quite figured out if these two interests belong in the same GitHub repo or not. But for now - they are all here!

Projects are often inspired by things found wild on the net, or ideas from the many great electronics and scale modelling podcasts and YouTube channels. Feel free to borrow liberally, and if you spot any issues do let me know (or send a PR!). See the individual projects for credits where due.