# TMP112

**Texas Instruments** · Temperature sensor · SOT-563

Reports board or ambient temperature over I2C to +/-0.5 C without calibration, in a tiny SOT-563. Twelve-bit resolution gives 0.0625 C steps across -40 to 125 C, an ALERT output fires on programmable high/low limits for thermostat use, and an address pin (ADD0) allows up to four devices on one bus. It runs from 1.4 to 3.6 V at a few microamps, so it fits battery designs. A small, accurate alternative to a thermistor plus ADC.

## Pinout

| Pin | Name | Type | Function |
|---|---|---|---|
| 1 | SCL | input | I2C/SMBus serial clock input. Open-drain bus line; requires an external pullup to V+. Voltage rating -0.5 V to 4 V. |
| 2 | GND | power_in | Device ground / negative supply reference. Note: pin 1 has curved edges in TMP112Dx packages (not applicable to SOT563). |
| 3 | ALERT | output | Overtemperature alert, open-drain output; requires an external pullup resistor. If unused, tie to GND (preferred). |
| 4 | ADD0 | input | I2C address-select input. Tie to V+, GND, SDA, or SCL to select one of four 7-bit slave addresses, allowing up to four TMP112 devices on one bus. |
| 5 | V+ | power_in | Positive supply input, 1.4 V to 3.6 V (3.3 V nominal). Absolute maximum 4 V. Typical quiescent current 3.2 uA. |
| 6 | SDA | bidirectional | I2C/SMBus serial data line. Open-drain output; requires an external pullup to V+. Voltage rating -0.5 V to 4 V. |

## Key specifications

| Parameter | Value |
|---|---|
| Type | Digital temperature sensor |
| Interface | I2C / SMBus (4 addresses) |
| Accuracy | +/-0.5 C (max, -25 to 85 C) |
| Resolution | 12-bit (0.0625 C) |
| Range | -40 to 125 C |
| Alert | Programmable high/low limit output |
| Supply | 1.4-3.6 V |
| Package | SOT-563 |

## Ordering variants

Same part, different packaging or reel option.

- `TMP112AIDRLR (SOT-563, +/-0.5 C)`
- `TMP112BIDRLR (wider range)`
- `TMP112NAIDRLR (relaxed accuracy)`

## CAD (KiCad official)

- Symbol: `Sensor_Temperature:TMP112xxDRL (KiCad official)`
- Footprint: `Package_TO_SOT_SMD:SOT-563`
- 3D model: SOT-563 (KiCad packages3D, STEP)
- 3D model files: `tmp112-etched.step` / `tmp112-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `tmp112.step` / `tmp112.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [Texas Instruments datasheet](https://www.ti.com/lit/ds/symlink/tmp112.pdf) (46 pp, sha256 `5e9dc199169e25b3`, 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/tmp112-datasheet.pdf)