#152 LD1117 Regulator
Test an LD1117 3.3V linear regulator
The LD1117 is a low drop fixed and adjustable voltage regulator, available from a number of manufacturers including UTC and ST. Parts are available for a range of output voltages, including: 1.2V, 1.5V, 1.8V, 2.5V, 2.85V, 3.0V, 3.3V, 3.6V, 5.0V, and ADJ.
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
Note that the LD1117A by ST has a different pin configuration for the TO220 package. From pin 1 left front: Ground, Vout, Vin.
Some DMM measurements, with a 10kΩ output load:
|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!