# AP7381-33SA-7

**Diodes Incorporated** · Linear regulator (LDO) · SOT23 (SA)

Diodes Incorporated AP7381-33SA-7: a fixed 3.3 V, 150 mA low-dropout linear regulator with a wide input range (up to 40 V) and very low quiescent current, in a 3-pin SOT23.

## Verification

A person checks each page against its datasheet and signs it off here; the badge turns amber if a checked file changes.

::adom-verified{src="/adom/ap7381-33sa-7/render/verification.json"}

## Pinout

| Pin | Name | Type | Function |
|---|---|---|---|
| 1 | VOUT | power_out | Regulated 3.3 V output (ds p.2) |
| 2 | GND | power_in | Ground (ds p.2) |
| 3 | VIN | power_in | Input, up to 40 V (ds p.2) |

## Key specifications

| Parameter | Value | Source |
|---|---|---|
| Output voltage | 3.3 V, ±2 % (VOUT x 98 % to x 102 %) | datasheet p.3 |
| Output current | 150 mA | datasheet p.2 |
| Input voltage (operating) | up to 40 V | datasheet p.2 |
| Input voltage (absolute maximum) | -0.3 to 45 V | datasheet p.2 |
| Dropout | 1000 mV at 100 mA | datasheet p.1, p.3 |
| Output temperature coefficient | ±100 ppm/°C | datasheet p.3 |
| Operating junction temperature | -40 to +125 °C | datasheet p.2 |
| Package | SOT23, 3 pins (SA) | datasheet p.1, p.2 |

## Ordering

| Distributor | Part number | Stock (2026-11-03) | Note |
|---|---|---|---|
| Mouser | [621-AP7381-33SA-7](https://www.mouser.com/en/ProductDetail/Diodes-Incorporated/AP7381-33SA-7?qs=y6ZabgHbY%252ByfboEZm%252BnPlA%3D%3D) | 427,379 | lead time 280 Days, $0.29 each |
| DigiKey | [31-AP7381-33SA-7TR-ND](https://www.digikey.com/en/products/detail/diodes-incorporated/AP7381-33SA-7/9765648) | | number from a DigiKey lookup on 2026-11-03 |
| LCSC / JLCPCB | not looked up | | |

## CAD

| File | What it is |
|---|---|
| `ap7381-33sa-7.kicad_sym` | KiCad symbol from KiCad's `Regulator_Linear:AP7381-33SA-7`, with MPN, manufacturer, Mouser and DigiKey numbers as properties |
| `ap7381-33sa-7.kicad_mod` | KiCad footprint: KiCad's `Package_TO_SOT_SMD:SOT-23` |
| `ap7381-33sa-7.step` / `ap7381-33sa-7.glb` | 3D model, Z-up, seated on z = 0: KiCad packages3D SOT-23.step (KiCad 10.0.4 library on noah-asus), unmodified |
| `ap7381-33sa-7-etched.step` / `ap7381-33sa-7-etched.glb` | The same model with the part number laser-etched on top as a separate `Adom.LaserEtch` group (a virtual identification aid, not the maker's real marking) |
| `ap7381-33sa-7.lbr` | Fusion 360 / EAGLE library: one deviceset with MPN, MANUFACTURER, MOUSER_PN and DIGIKEY_PN attributes |
| `altium/Adom_ap7381_33sa_7.SchLib` / `.PcbLib` | Altium library pair (adom-lbr, no Altium needed), parameters carry the part numbers; `altium/*.adom-lbr.json` is the hub it was built from |
| `provenance/files.json` | Every file on this page: source, retrieval date, SHA-256, authoring class and generator |

## Provenance

- **Datasheet:** [docs/ap7381-33sa-7-datasheet.pdf](docs/ap7381-33sa-7-datasheet.pdf) (DS39917 Rev. 5-2), from [www.diodes.com](https://www.diodes.com/assets/Datasheets/AP7381.pdf), retrieved 2026-10-30.
- **Specs:** each row names its datasheet page.
- **Mouser number and stock:** looked up 2026-11-03 with adom-mouser; DigiKey number with adom-digikey; exact part number and manufacturer.
- **Footprint:** KiCad 10.0.4 library `Package_TO_SOT_SMD:SOT-23`, unmodified apart from its name.
- **3D:** KiCad packages3D SOT-23.step (KiCad 10.0.4 library on noah-asus), unmodified.

## Related

- First used on the [AM32 ESC Molecule v1](https://wiki.adom.inc/adom/am32-esc-v1) (private project page).