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Project Notes

#152 PowerLD1117

Test an LD1117 3.3V linear regulator

Notes

The LD1117 is a low drop fixed and adjustable voltage regulator, available from a number of manufacturers including UTC and ST.

The component I have is marked: UTC LD1117AL 33D010HT5

Although I can’t find a datasheet that matches these markings exactly, I figure:

  • A = 1A
  • L = lead free
  • 33 = 3.3V
  • D? = pin out is (from left front): Vin, Ground, Vout

Some DMM measurements, with a 10kΩ output load:

Vin Iin Vout Iout Pin:Pout
5.10V 2.47mA 3.30V 329µA 12.6mW : 1.09mW

The inefficiency of a linear regulator is clear to see - we’re dissipating 11.51mW in the 1117, far more power than is actually delivered to the load. But they’re convenient!

Construction

Breadboard

The Schematic

The Build

Credits and References

About LEAP#152 Power
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LEAP is my personal collection of electronics projects, 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 (IMHO!).

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Feel free to borrow liberally, and if you spot any issues do let me know. See the individual projects for credits where due. There are even now a few projects contributed by others - send your own over in a pull request if you would also like to add to this collection.