# LM317LD

**UMW** · Voltage Regulators - Linear, Low Drop Out (LDO) Regulators · SOP-8

LM317LD from UMW, in a SOP-8. Pinout and pin descriptions extracted from the manufacturer datasheet (extract_pins, cross-checked by a second model); symbol, footprint, and 3D from KiCad-official CAD.

## Pinout

| Pin | Name | Type | Function |
|---|---|---|---|
| 1 | VIN | power_in | Regulator input; input-output differential must not exceed 40V and must be at least 3V for the specified regulation. |
| 2 | VOUT | power_out | Regulated output, adjustable from 1.2 to 37V and supplying more than 0.1A of load current. |
| 3 | VOUT/3 | power_out | Additional regulated output pin (labelled VOUT/3 on the SOP-8 pinout), the third of the output pins. |
| 4 | ADJ | input | Adjustment pin that sets the output voltage via the R1/R2 divider (VO=1.25V(1+R2/R1)+Iadj R2), with IADJ typically 50µA. |
| 5 | NC/2 | unconnected | No connect pin (second NC, labelled NC/2 on the SOP-8 pinout). |
| 6 | VOUT/4 | power_out | Additional regulated output pin (labelled VOUT/4 on the SOP-8 pinout), the fourth of the output pins. |
| 7 | VOUT/2 | power_out | Additional regulated output pin (labelled VOUT/2 on the SOP-8 pinout), the second of the output pins. |
| 8 | NC | unconnected | No connect pin. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | UMW |
| Package | SOP-8 |
| Category | Power Management (PMIC) |
| Pins | 8 |

## CAD (KiCad official)

- Symbol: `LM317LD`
- Footprint: `Package_SO:SOIC-8_3.9x4.9mm_P1.27mm`
- 3D model: SOP-8 (KiCad packages3D, STEP)
- 3D model files: `lm317ld-etched.step` / `lm317ld-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `lm317ld.step` / `lm317ld.glb` are the bare package body.

## Provenance

Data extracted from the manufacturer datasheet, not a distributor listing:

- **Datasheet:** [UMW datasheet](https://jlcpcb.com/api/file/downloadByFileSystemAccessId/8755878702863257600) (8 pp, sha256 `47c632ae21db9ba9`, retrieved 2026-10-09, tier: lcsc)
- **Extractor:** parts-factory `2.0.0` / `extract_pins 0.3`, primary `claude-sonnet-5-5` (text+vision), consensus `claude-opus-5-5` (agreed), guards: pin_guards 0.1: passed. Pins are checked against the footprint pad set and their cited datasheet pages before publish.
- **CAD:** KiCad official libraries (CC-BY-SA 4.0).

[Datasheet PDF](docs/lm317ld-datasheet.pdf)