Q: LM317L Vdo by 1123732

I am using the LM317L in a 5 V to 3.3 V @ 100 mA application and need to know what the V drop-out spec is (not in the data sheet).

2. Is there a suitable LDO for this App. in a SOT-89 package (or alternate package that might fit in the same board footprint) that is pin compatible with the LM317L? I could not find a SOT-89 replacement.


Q: Re: LM317L Vdo by 10449

Although not specified in the datasheet, the dropout voltage could be somewhere between 1.5V to 2V at room temp.  The dropout voltage will increase at higher temperatures.

The LM317 or LM317L is not designed for low dropout voltages or low Vin to Vout differential voltages.  Note that datasheet specs are taken for input to output voltage differentials of 3V or higher.  I'm not aware of a direct pin to pin replacement for this linear regulator.  Note that the LM317L is a linear regulator, not an LDO (Low Dropout Regulator).