The DS18B20 digital thermometer provides 9 - to 12-digit Celsius temperature measurement and features a non-volatile alarm function with user programmable up and down trigger points. The DS18B20 communicates over a 1-wire bus, which by definition requires only one data line (and ground) to communicate with the central microprocessor.
Pin Configurations
In addition, the DS18B20 can obtain power directly from the data cable (" parasitic power ") without an external power supply. Each DS18B20 has a unique 64-bit serial code that allows multiple DS18B20s to work on the same 1-Wire bus.
DS18B20 Block Diagram
Thus, it is simple to use a single microprocessor to control multiple DS18B20s distributed over a large area. Applications that can benefit from this capability include HVAC environmental control, temperature monitoring systems inside buildings, equipment or machinery, and process monitoring and control systems.
DS18B20 Timing Diagrams
Pin Description
Features
● The Unique 1-Wire Interface Requires Only One Port Pin for Communication
● Reduce Component Count with Integrated Temperature Sensor and EEPROM
- Measures Temperatures from -55°C to +125°C (-67°F to +257°F)
- ±0.5°C Accuracy from -10°C to +85°C
- Programmable Resolution from 9 Bits to 12 Bits
- No External Components Required
● Parasitic Power Mode Requires Only 2 Pins for its use Operation (DQ and GND)
● Simplifies Distributed Temperature-Sensing Applications with Multidrop Capability
- Each Device Has a Unique 64-Bit Serial Code Stored in On-Board ROM
● Flexible User-Definable Nonvolatile (NV) Alarm Settings with Alarm Search Command Identifies Devices with Temperatures Outside Programmed Limits
● Available in 8-Pin SO (150 mils), 8-Pin µSOP, and 3-Pin TO-92 Packages
Applications
● Thermostatic control
● Industrial system
● Consumer Goods
● Thermometer
● Heat sensitive system
