DS18S20 High-Precision 1-Wire Digital Thermometer General Description Benefits and Features The DS18S20 digital thermometer provides 9-bit Celsius Unique 1-Wire Interface Requires Only One Port temperature measurements and has an alarm function Pin for Communication with nonvolatile user-programmable upper and lower trig- Maximize System Accuracy in Broad Range of ger points. The DS18S20 communicates over a 1-Wire Thermal Management Applications bus that by definition requires only one data line (and Measures Temperatures from -55C to +125C ground) for communication with a central microprocessor. (-67F to +257F) In addition, the DS18S20 can derive power directly from 0.5C Accuracy from -10C to +85C the data line (parasite power), eliminating the need for 9-Bit Resolution an external power supply. No External Components Required Each DS18S20 has a unique 64-bit serial code, which Parasite Power Mode Requires Only 2 Pins for allows multiple DS18S20s to function on the same 1-Wire Operation (DQ and GND) bus. Thus, it is simple to use one microprocessor to Simplifies Distributed Temperature-Sensing control many DS18S20s distributed over a large area. Applications with Multidrop Capability Applications that can benefit from this feature include Each Device Has a Unique 64-Bit Serial Code HVAC environmental controls, temperature monitoring Stored in On-Board ROM systems inside buildings, equipment, or machinery, and Flexible User-Definable Nonvolatile (NV) Alarm Settings process monitoring and control systems. with Alarm Search Command Identifies Devices with Temperatures Outside Programmed Limits Applications Thermostatic Controls Available in 8-Pin SO (150 mils) and 3-Pin TO-92 Industrial Systems Packages Consumer Products Thermometers Pin Configurations Thermally Sensitive Systems TOP VIEW + N.C. 1 8 N.C. DS18S20 2 DS18S20 7 N.C. N.C. 1 2 3 3 6 N.C. VDD 4 5 DQ GND SO (150 mils) (DS18S20Z) GND DQ VDD 1 2 3 1 Ordering Information appears at end of data sheet. BOTTOM VIEW TO-92 1-Wire is a registered trademark of Maxim Integrated Products, Inc. (DS18S20) 19-5474 Rev 3 4/15DS18S20 High-Precision 1-Wire Digital Thermometer Absolute Maximum Ratings Voltage Range on Any Pin Relative to Ground ....-0.5V to +6.0V Storage Temperature Range ............................ -55C to +125C Continuous Power Dissipation (T = +70C) Lead Temperature (soldering, 10s) .................................+260C A 8-Pin SO (derate 5.9mW/C above +70C) ..............470.6mW Soldering Temperature (reflow) 3-Pin TO-92 (derate 6.3mW/C above +70C) ............500mW Lead(Pb)-free...............................................................+260C Operating Temperature Range ......................... -55C to +125C Containing lead(Pb) .....................................................+240C These are stress ratings only and functional operation of the device at these or any other conditions above those indicated in the operation sections of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods of time may affect reliability. DC Electrical Characteristics (V = 3.0V to 5.5V, T = -55C to +125C, unless otherwise noted.) DD A PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS Supply Voltage V Local Power (Note 1) +3.0 +5.5 V DD Parasite Power +3.0 +5.5 Pullup Supply Voltage V (Note 1, 2) V PU Local Power +3.0 V DD -10C to +85C 0.5 Thermometer Error t (Note 3) C ERR -55C to +125C 2 Input Logic-Low V (Note 1, 4, 5) -0.3 +0.8 V IL The lower of Local Power +2.2 Input Logic-High V (Note 1, 6) 5.5 or V V IH DD Parasite Power +3.0 + 0.3 Sink Current I V = 0.4V (Note 1) 4.0 mA L I/O Standby Current I (Note 7, 8) 750 1000 nA DDS Active Current I V = 5V (Note 9) 1 1.5 mA DD DD DQ Input Current I (Note 10) 5 A DQ Drift (Note 11) 0.2 C Note 1: All voltages are referenced to ground. Note 2: The Pullup Supply Voltage specification assumes that the pullup device is ideal, and therefore the high level of the pul- lup is equal to V . In order to meet the V spec of the DS18S20, the actual supply rail for the strong pullup transistor PU IH must include margin for the voltage drop across the transistor when it is turned on thus: V = V + PU ACTUAL PU IDEAL V . TRANSISTOR Note 3: See typical performance curve in Figure 1. Note 4: Logic-low voltages are specified at a sink current of 4mA. Note 5: To guarantee a presence pulse under low voltage parasite power conditions, VILMAX may have to be reduced to as low as 0.5V. Note 6: Logic-high voltages are specified at a source current of 1mA. Note 7: Standby current specified up to +70C. Standby current typically is 3A at +125C. Note 8: To minimize I , DQ should be within the following ranges: GND DQ GND + 0.3V or V 0.3V DQ V . DDS DD DD Note 9: Active current refers to supply current during active temperature conversions or EEPROM writes. Note 10: DQ line is high (high-Z state). Note 11: Drift data is based on a 1000-hour stress test at +125C with V = 5.5V. 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