LM317 / LM338 regulator (LM317T, TO-220)
LM317T adjustable linear regulator · V_out = 1.25 V × (1 + R2/R1) · 1.5 A · max 40 V in−out · on a heatsink (≈ 12 °C/W)
Try it on the benchThe lab drops it on an empty bench and opens its datasheet card.
Typical part: LM317T (TO-220)
Pins
- ADJ
- OUT
- IN
Ratings and limits
| Input − output | 3–40 V |
|---|---|
| Output current | 1.5 A |
| Reference | 1.25 V |
| Thermal shutdown | ≈ 150 °C |
How to use it
Adjustable regulator: V_out = 1.25 V × (1 + R2/R1), with R1 = 240 Ω from OUT to ADJ. Also a constant-current source with one resistor: I = 1.25 V / R.
Lessons and builds that use it
- LM317 adjustable regulator
- Li-ion CC/CV charger from an LM317
- Adjustable bench supply 1.25–20 V (build)
- 65 W USB-C PD stage on a ready-made 24 V supply: buck converter, PD controller, load switch (build)