DS1820

Product Summary

The DS1820 digital thermometer provides 9-bit Celsius temperature measurements and has an alarm function with nonvolatile user-programmable upper and lower trigger points. The DS1820 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℃ to +125℃ and is accurate to ±0.5℃ over the range of –10℃ to +85℃. In addition, the DS18S20 can derive power directly from the data line (“parasite power”), eliminating the need for an external power supply. Each DS1820 has a unique 64-bit serial code, which allows the device to function on the same 1-Wire bus. Thus, it is simple to use one microprocessor to control many DS1820s 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.

Parametrics

DS1820 absolute maximum ratings: (1)Voltage Range on Any Pin Relative to Ground: -0.5V to +6.0V; (2)Continuous Power Dissipation (TA = +70℃): 8-Pin SO (derate 5.9mW/℃ above +70℃): 470.6mW; 3-Pin TO-92 (derate 6.3mW/℃ above +70℃): 500mW; (3)Operating Temperature Range : -55℃ to +125℃; (4)Storage Temperature Range: -55℃ to +125℃; (5)Lead Temperature (soldering, 10s): +260℃; (6)Soldering Temperature (reflow): Lead(Pb)-free : +260℃; Containing lead(Pb): +240℃.

Features

DS1820 features: (1)Unique 1–Wire interface requires only one port pin for communication; (2)Multidrop capability simplifies distributed temperature sensing applications; (3)Requires no external components; (4)Can be powered from data line. Power supply range is 3.0V to 5.5V; (5)Zero standby power required; (6)Measures temperatures from –55℃ to +125℃; (7)±0.5℃ accuracy from –10℃ to +85℃; (8)Temperature is read as a 9–bit digital value; (9)Converts temperature to digital word in 750 ms (max.); (10)User–definable, nonvolatile temperature alarm settings; (11)Alarm search command identifies and addresses devices whose temperature is outside of programmed limits (temperature alarm condition); (12)Functionally compatible with DS1820 1-Wire digital thermometer; (13)Applications include thermostatic controls, industrial systems, consumer products, thermometers, or any thermally sensitive system.

Diagrams