Explore LM1117-3.3 pins, signal names, electrical functions and connection guidance for each package.
Select a pin to explore its connection
Click a lead or use the arrow keys. Front view · marking toward you · leads down
Return for the internal reference, feedback divider and bias current in the fixed 3.3 V version.
Connect to the input-supply return, load return and both capacitor returns.
This is GND on the fixed-output part. The adjustable LM1117 uses this lead as ADJ and is a different circuit.
Supplies the nominal 3.3 V rail. The metal tab is electrically connected to this output.
Connect the load and a suitable output capacitor close to the regulator.
The output capacitor is part of the stability requirements: TI specifies at least 10 µF tantalum with ESR from 0.3 Ω to 22 Ω. The tab is not ground.
Feeds the pass stage and bias circuit from a supply above the output by sufficient headroom.
Use a regulated 5 V source for the example and a local 10 µF input bypass.
Check input tolerance, ripple and dropout at the intended load and temperature. The 20 V absolute maximum is not the 15 V recommended maximum.
BETA