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.
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!
- LD1117 datahseet
- Linear Regulator - wikipedia