1-Wire
An open-drain multidrop bus with a unique 64-bit ROM identifier per device. External power keeps DQ available for conversion-status polling.
DS18B20 1-Wire thermometer pinout
The DS18B20 is an individually addressable 1-Wire temperature sensor with programmable 9- to 12-bit conversion.
Micro small-outline package.
µSOP / FSOP-8 pinout
3 · NC
No internal connection. Leave electrically open unless the package notes specify otherwise.
All 8 pins
| Pin | Signal | Direction | Function |
|---|---|---|---|
| 1 | DQ Open drain | Open drain | 1-Wire data. The same wire can supply the device in parasite-power mode. |
| 2 | NC None | None | No internal connection. Leave electrically open unless the package notes specify otherwise. |
| 3 | NC None | None | No internal connection. Leave electrically open unless the package notes specify otherwise. |
| 4 | GND Supply return | Supply return | Connect to the common ground plane or bench return. |
| 5 | NC None | None | No internal connection. Leave electrically open unless the package notes specify otherwise. |
| 6 | NC None | None | No internal connection. Leave electrically open unless the package notes specify otherwise. |
| 7 | NC None | None | No internal connection. Leave electrically open unless the package notes specify otherwise. |
| 8 | VDD Supply input | Supply input | Device supply. Place the bypass capacitor close to this pin. |
Signal assignments
Electrical limits
| Parameter | Limit | Conditions and source |
|---|---|---|
| External supply3.0–5.5 V | 3.0–5.5 V | Tie VDD to ground when using parasite power. Analog Devices / Maxim DS18B20 Rev. 6, pp. 1–5, 8 and 19. |
| Conversion time750 ms maximum | 750 ms maximum | 12-bit conversion. Lower resolution settings convert faster. Analog Devices / Maxim DS18B20 Rev. 6, pp. 1–5, 8 and 19. |
| Temperature accuracy±0.5 °C | ±0.5 °C | From −10 to +85 °C. Overall measurement range is −55 to +125 °C. Analog Devices / Maxim DS18B20 Rev. 6, pp. 1–5, 8 and 19. |
Models and documents
The three package maps cover the bare sensor. Check polarity separately on cabled probes or third-party modules.
- DS18B20U
- Micro small-outline package.
- DS18B20U+
- Micro small-outline package.
- DS18B20U/T&R
- Micro small-outline package.
- DS18B20U+T&R
- Micro small-outline package.
- DS18B20 manufacturer documentation· Analog Devices / Maxim DS18B20 Rev. 6, pp. 1–5, 8 and 19.