1-Wire Parasite-Power Digital Thermometer

The DS18S20 digital thermometer provides 9-bit Celsius temperature measurements and has an alarm function with nonvolatile user-programmable upper and lower trigger points. The DS18S20 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 DS18S20 can derive power directly from the data line ("parasite power"), eliminating the need for an external power supply.

Each DS18S20 has a unique 64-bit serial code, which allows multiple DS18S20s to function on the same 1-Wire bus. Thus, it is simple to use one microprocessor to control many DS18S20s distributed over a large area. Applications that can benefit from this feature include HVAC environmental controls, temperature monitoring systems inside buildings, equipment, or machinery, and process monitoring and control systems.

Applications

* Consumer Products * Industrial Systems * Thermally Sensitive Systems * Thermometers * Thermostatic Controls

* Unique 1-Wire® Interface Requires Only One Port Pin for Communication

* Maximize System Accuracy in Broad Range of Thermal Management Applications

* Measures Temperatures from -55°C to +125°C (-67°F to +257°F)

* ±0.5°C Accuracy from -10°C to +85°C

* 9-Bit Resolution

* No External Components Required

* Parasite 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) and 3-Pin TO-92 Packages