سنسور دما دیجیتال ds18b20

Description :

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.

The 64-bit ROM stores the device’s unique serial code.

The scratchpad memory contains the 2-byte temperature register that stores the digital output from the temperature sensor. In addition, the scratchpad

provides access to the 1-byte upper and lower alarm trigger registers (TH and TL) and the 1-byte configuration register.

The configuration register allows the user to set the resolution of the temperature to digital conversion to 9, 10, 11, or 12 bits. The TH, TL, and configuration registers are nonvolatile (EEPROM), so they will retain data when the device is powered down.

Another feature of the DS18B20 is the ability to operate without an external power supply. Power is instead supplied through the 1-Wire pullup resistor via the DQ pin when the bus is high.

The high bus signal also charges an internal capacitor (CPP), which then supplies power to the device when the bus is low.

 

Applications:

Measuring temperature at hard environments

Liquid temperature measurement

Applications where the temperature has to be measured at multiple points

 

Features:

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 Limit