DS18B20 Temperature Sensor – Precise 1‑Wire Digital Thermometer for Industrial & Consumer Use

The DS18B20 is a highly reliable digital temperature sensor that operates over a single‑wire interface, enabling accurate readings from –55 °C to +125 °C (–67 °F to +257 °F) with ±0.5 °C precision. Its 9‑ to 12‑bit resolution and 750 ms conversion time make it ideal for both low‑power applications and fast monitoring systems.

Why the DS18B20 Stands Out

Unlike traditional analog sensors, the DS18B20 communicates via a proprietary 1‑Wire protocol, requiring only one data pin for power, control, and data. Each sensor is uniquely addressed with a 64‑bit serial number, allowing dozens of units to share a single microcontroller pin without collision.

Pin Configuration

Below is the typical pinout for the DS18B20:

• Pin 1 – Ground: Connects to the circuit’s GND.
• Pin 2 – Vcc: Supplies 3.0 V to 5.5 V; can also be powered parasitically from the data line.
• Pin 3 – Data: Carries the 1‑Wire data stream and, when powered parasitically, supplies the sensor’s voltage.

Key Specifications

• Digital, programmable temperature sensor.
• 1‑Wire communication, 64‑bit unique address.
• Power supply: 3.0 V – 5.5 V.
• Temperature range: –55 °C to +125 °C (–67 °F to +257 °F).
• Accuracy: ±0.5 °C.
• Resolution: 9‑ to 12‑bit (default 12‑bit).
• Conversion time: 750 ms.
• Parasitic power support.
• Programmable alarm thresholds.
• Available in SOP, TO‑92, and waterproof packages.

How It Works

Upon receiving a Convert T command, the DS18B20 samples the ambient temperature, converts it to a 12‑bit digital value, and stores it in a 2‑byte register. The sensor then returns to an inactive state until the next command, minimizing power draw. With an external power supply, the master can read the data during conversion, allowing real‑time monitoring.

Typical Applications

• Industrial process control in mining, chemical processing, and soil monitoring.
• Liquid temperature measurement in HVAC, refrigeration, and water‑based systems.
• Thermostat control units for homes and commercial buildings.
• Portable thermometers and handheld devices.
• Temperature logging in harsh environments.
• Multi‑point temperature arrays for system diagnostics.

Whether you need a rugged, waterproof module for hydro‑projects or a standard surface‑mount sensor for a PCB, the DS18B20 delivers consistent performance and ease of integration.