lm317 3.3 v schematic diagram

lm317 3.3 v schematic diagram

The more expensive LM117 uses a 240 ohm resistor for R1. The LM317 is supposed to use a 120 om resistor or less so that its output voltage doesn't rise without a load if it has its max rated operating current and if its input voltage is high.




With 120 ohms for R1 and 360 ohms for R2 the output is 5.0V.

with 120 ohms for R1 and 200 ohms for R2 the output voltage is 3.333V.

These resistors are common 5% values.