DS18S20 High-Precision 1-Wire Digital Thermometer General Description 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. It has an operating temperature range of 55°C to +125°C and is accurate to ±0.5°C over the range of 10°C to +85°C. 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. Benefits and Features 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 Applications Thermostatic Controls Industrial Systems Consumer Products Thermometers Thermally Sensitive Systems Pin Configurations
TOP VIEW DS18S20
1 2 3 N.C. N.C. VDD GND 1 2 3 4 + DS18S20 8 7 6 5 N.C. N.C. N.C. GND SO (150 mils) (DS18S20Z) GND DQ VDD 2 3 1 Ordering Information appears at end of data sheet. 1-Wire is a registered trademark of Maxim Integrated Products, Inc. BOTTOM VIEW 1 TO-92 (DS18S20) 19-5474; Rev 2; 1/15 DS18S20 High-Precision 1-Wire Digital Thermometer Absolute Maximum Ratings
Voltage Range on Any Pin Relative to Ground .-0.5V to +6.0V Continuous Power Dissipation (TA = +70°C) 8-Pin SO (derate 5.9mW/°C above +70°C).470.6mW 3-Pin TO-92 (derate 6.3mW/°C above +70°C) .500mW Operating Temperature Range . -55°C to +125°C Storage Temperature Range . -55°C to +125°C Lead …