# REF3318AIDBZR

**Texas Instruments** · Voltage Reference · SOT-23

REF3318AIDBZR from Texas Instruments, in a SOT-23. 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 | IN | power_in | Input supply voltage. Must be at least VOUT + 200 mV up to 5.5 V (absolute max 7.5 V). Bypass to GND with a low-ESR capacitor per the power-supply recommendations. |
| 2 | OUT | output | Reference output voltage (1.8 V nominal for REF3318). Sources or sinks up to ±5 mA (30 mA max). Requires a 0.1 µF to 10 µF load capacitor for stability; short-circuit current limited to ~35 mA typ. |
| 3 | GND | power_in | Device ground. Common return for input supply and output reference voltage. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | Texas Instruments |
| Package | SOT-23 |
| Category | PMIC |
| Pins | 3 |

## Ordering variants

Same part, different packaging or reel option.

- `REF3318AIDBZR`
- `REF3318AIDBZT`
- `REF3318AIDBZRIDCKR`
- `REF3318AIDBZRIDCKT`
- `REF3318AIDBZRIRSER`
- `REF3318AIDBZRIRSET`

## Electrical characteristics

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

| Parameter | Symbol | Min | Typ | Max | Unit | Conditions | Page |
|---|---|---|---|---|---|---|---|
| Initial accuracy |  | -0.15 |  | 0.15 | % |  | 6 |
| Output voltage temperature drift | dVOUT/dT |  | 9 | 30 | ppm/°C | –40°C to 85°C | 6 |
| Output voltage temperature drift | dVOUT/dT |  | 8 | 30 | ppm/°C | –40°C to 125°C | 6 |
| Line regulation | ΔVO(ΔVI) | -50 | 6 | 50 | ppm/V | VIN = VOUT + 200 mV to 5.5 V | 6 |
| Load regulation | ΔVO(ΔIL) | -50 | 6 | 50 | ppm/mA | VIN = VOUT + 200 mV | 6 |
| Minimum dropout voltage | VIN – VOUT |  | 110 | 160 | mV | ILOAD = ±5 mA | 6 |
| Capacitive load |  | 0.1 |  | 10 | μF |  | 6 |
| Quiescent current IQ | IQ |  | 3.9 | 5 | µA |  | 7 |
| Quiescent current IQ | IQ |  | 4.4 | 6.5 | µA | –40°C to 85°C | 7 |
| Quiescent current IQ | IQ |  | 4.8 | 8.5 | µA | –40°C to 125°C | 7 |
| Specified supply voltage range VS | VS |  |  | 5.5 | V |  | 7 |
| Operating supply voltage range |  |  |  | 5.5 | V | ILOAD = 0 mA | 7 |
| Specified temperature range | TA | -40 |  | 125 | °C |  | 7 |
| Operating temperature range | TA | -50 |  | 150 | °C |  | 7 |
| Input voltage |  |  |  | 7.5 | V |  | 5 |
| Output voltage |  |  |  | 5 | V |  | 5 |
| Output short-circuit current | ISC |  |  | 180 | mA |  | 5 |
| Operating temperature |  | -50 |  | 150 | °C |  | 5 |
| Junction temperature | TJ |  |  | 150 | °C |  | 5 |
| Storage temperature | Tstg | -65 |  | 150 | °C |  | 5 |
| Supply input voltage | VIN |  |  | 5.5 | V |  | 5 |
| Output current range | IOUT | -30 |  | 30 | mA |  | 5 |
| Junction-to-ambient thermal resistance (DBZ, SOT-23) | RθJA |  | 313.1 |  | °C/W |  | 5 |
| Junction-to-case (top) thermal resistance (DBZ, SOT-23) | RθJC(top) |  | 144 |  | °C/W |  | 5 |
| Junction-to-board thermal resistance (DBZ, SOT-23) | RθJB |  | 109.3 |  | °C/W |  | 5 |
| Junction-to-top characterization parameter (DBZ, SOT-23) | ψJT |  | 18.2 |  | °C/W |  | 5 |
| Junction-to-board characterization parameter (DBZ, SOT-23) | ψJB |  | 107.9 |  | °C/W |  | 5 |

## CAD (KiCad official)

- Symbol: `REF3318AIDBZR`
- Footprint: `Package_TO_SOT_SMD:SOT-23`
- 3D model: SOT-23 (KiCad packages3D, STEP)
- 3D model files: `ref3318aidbzr-etched.step` / `ref3318aidbzr-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `ref3318aidbzr.step` / `ref3318aidbzr.glb` are the bare package body.

## 3D model downloads

Two STEP files. Same geometry, different body top:

| File | Size | Use it when |
|---|---|---|
| [`ref3318aidbzr.step`](ref3318aidbzr.step) | 59 KB | You want the bare part, or you mark your own boards. |
| [`ref3318aidbzr-etched.step`](ref3318aidbzr-etched.step) | 2.3 MB | You want the part with `REF3318AIDBZR` already on it. |

The marking in the etched file is real recessed geometry cut into the solid, not a
texture or a decal: 562 faces against 69 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:** [Texas Instruments datasheet](https://www.ti.com/lit/ds/symlink/ref3318aidbzr.pdf) (37 pp, sha256 `4f68e657e0bb2b6e`, retrieved 2026-08-17, tier: manufacturer)
- **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/ref3318aidbzr-datasheet.pdf)