# LM7905S

**HGSEMI** · Voltage Regulators - Linear, Low Drop Out (LDO) Regulators · TO-263-3

LM7905S from HGSEMI, in a TO-263-3. Pinout and pin descriptions extracted from the manufacturer datasheet by ds2sf; symbol, footprint, and 3D from KiCad-official CAD.

## Pinout

| Pin | Name | Type | Function |
|---|---|---|---|
| 1 | GND | power_in | Ground / common return for the regulator. Both input and output voltages are referenced to this pin. |
| 2 | INPUT | power_in | Unregulated negative input supply. For LM7905 operating range is -7.0 V >= VIN >= -20 V (absolute max -35 V). Requires a 2.2 uF input decoupling capacitor to ground. |
| 3 | OUTPUT | power_out | Regulated -5.0 V output (typ.), -4.82 V to -5.18 V over 5 mA to 1.0 A load. Requires >=1.0 uF output capacitor to ground for stability. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | HGSEMI |
| Package | TO-263-3 |
| Category | PMIC |
| Pins | 3 |

## Ordering variants

Same part, different packaging or reel option.

- `LM7905SS/TR`
- `LM7905ST`
- `LM7905SS2/TR`

## CAD (KiCad official)

- Symbol: `LM7905S`
- Footprint: `Package_TO_SOT_SMD:TO-263-2`
- 3D model: TO-263-3 (KiCad packages3D, STEP)
- 3D model files: `lm7905s-etched.step` / `lm7905s-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `lm7905s.step` / `lm7905s.glb` are the bare package body.

## 3D model downloads

Two STEP files. Same geometry, different body top:

| File | Size | Use it when |
|---|---|---|
| [`lm7905s.step`](lm7905s.step) | 108 KB | You want the bare part, or you mark your own boards. |
| [`lm7905s-etched.step`](lm7905s-etched.step) | 1.3 MB | You want the part with `LM7905S` already on it. |

The marking in the etched file is real recessed geometry cut into the solid, not a
texture or a decal: 344 faces against 79 in the bare model. It
survives export, section views, and rendering in any CAD tool, and it drops straight
into KiCad or Fusion with no extra setup.

## Provenance

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

- **Datasheet:** [HGSEMI datasheet](docs/lm7905s-datasheet.pdf) (10 pp, sha256 `7e5f09b8cf107bcf`, retrieved 2026-08-17, tier: lcsc)
- **Extractor:** `ds2sf` (Claude). Every pin and dimension is cited to a datasheet page; it refuses to fabricate.
- **CAD:** KiCad official libraries (CC-BY-SA 4.0).

[Datasheet PDF](docs/lm7905s-datasheet.pdf)