# LM317D2T

**MSKSEMI** · Voltage Regulators - Linear, Low Drop Out (LDO) Regulators · TO-263

LM317D2T from MSKSEMI, in a TO-263. 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 | IN | power_in | Input pin for the unregulated supply; the datasheet limits the input-output voltage difference (VI-VO) to 40 V maximum. |
| 2 | GND | power_in | Ground pin as labelled in the datasheet pinout; the datasheet gives no further functional description for this pin. |
| 3 | OUT | power_out | Regulated output pin, adjustable from 1.3 V to 37 V with output current up to 1.5 A. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | MSKSEMI |
| Package | TO-263 |
| Category | Power Management (PMIC) |
| Pins | 3 |

## Electrical characteristics

Limits as printed in the datasheet (page.json `metadata.characteristics` carries them as data).

| Parameter | Symbol | Min | Typ | Max | Unit | Conditions | Page |
|---|---|---|---|---|---|---|---|
| Input - Output Voltage Difference | VI-VO |  |  | 40 | V |  | 3 |
| Lead Temperature | TLEAD |  |  | 230 | ℃ |  | 3 |
| Storage Temperature Range | TSTG | -65 |  | 150 | ℃ |  | 3 |
| Operating Temperature Range | TOPR | 0 |  | 125 | ℃ |  | 3 |
| Line Regulation | ΔVO |  | 0.01 | 0.04 | %/V | Ta=25 C,3V<=VI-VO<=40V | 3 |
| Line Regulation | ΔVO |  | 0.02 | 0.07 | %/V | Ta=0 - 125 C,3V<=VI-VO<=40V | 3 |
| Line Regulation | ΔVO |  | 18 | 25 | mV | Ta=25 C VO<=6V | 3 |
| Load Regulation | ΔVO |  | 0.4 | 0.5 | %/VO | 10mA<=IO<=IMAX VO>=5V | 3 |
| Load Regulation | ΔVO |  | 40 | 70 | mV | 10mA<=IO<=IMAX VO<=5V | 3 |
| Load Regulation | ΔVO |  | 0.8 | 1.5 | %/VO | VO>=6V | 3 |
| Adjustable Pin Current | IADJ |  | 46 | 100 | μA |  | 3 |
| Adjustable Pin Current Change | ΔIADJ |  | 2 | 5 | μA | 2.5V<=VI-VO<=40V, 10mA<=Io<=IMAX, PD<=PMAX | 3 |
| Reference Voltage | VREF | 1.2 | 1.25 | 1.3 | V | 3V<=VI-VO<=40V, 10mA<=IO<=IMAX,PD<=PMAX | 3 |
| Minimum Load Current for Regulation | IL(MIN) |  | 3.5 | 10 | mA | VI-VO=40V | 3 |
| Maximum Output Current | IO(MAX) |  | 1.5 | 2.2 | A | VI-VO<=15V, PD<=PMAX | 3 |
| Maximum Output Current | IO(MAX) |  | 0.15 | 0.4 | A | VI-VO<=15V, PD<=PMAX, Ta=25 C | 3 |
| RMS Noise v.s. % of Vout | eN |  | 0.003 | 0.01 | %/VO | TA=25 C,10HZ<=f<=10KHZ | 3 |
| Long-term Stability | ST |  | 0.3 | 1 | % | TJ=THIGH; TA=25 C,1000 hr | 3 |
| Junction to Case Thermal Resistance | RθJC |  | 5 |  | C/W |  | 3 |
| Temperature Stability | STT |  | 0.7 |  | %/VO |  | 3 |
| Ripple Rejection | RR |  | 60 |  | dB | VO=10V,f=120HZ | 3 |
| Ripple Rejection | RR |  | 75 |  | dB | VO=10V,f=120HZ,CADJ=10 μF | 3 |

## CAD (KiCad official)

- Symbol: `LM317D2T`
- Footprint: `Package_TO_SOT_SMD:TO-263-2`
- 3D model: TO-263 (KiCad packages3D, STEP)
- 3D model files: `lm317d2t-etched.step` / `lm317d2t-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `lm317d2t.step` / `lm317d2t.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [MSKSEMI datasheet](https://jlcpcb.com/api/file/downloadByFileSystemAccessId/8590922592784101376) (6 pp, sha256 `ab7f9e35d35eae9e`, retrieved 2026-10-20, tier: lcsc)
- **Extractor:** parts-factory `2.0.0` / `extract_pins 0.3`, primary `claude-haiku-5-5` (text), consensus `claude-sonnet-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/lm317d2t-datasheet.pdf)