The DS18B20 digital thermometer provides 9-bit to 12-bit
Celsius temperature measurements and has an alarm
function with nonvolatile user-programmable upper and
lower trigger points. The DS18B20 communicates over a
1-Wire bus that by definition requires only one data line
(and ground) for communication with a central microprocessor. In addition, the DS18B20 can derive power
directly from the data line (“parasite power”), eliminating
the need for an external power supply.
Each DS18B20 has a unique 64-bit serial code, which
allows multiple DS18B20s to function on the same 1-Wire
bus. Thus, it is simple to use one microprocessor to
control many DS18B20s distributed over a large area.
● 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
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