Dallas DS1820 free download

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DS1820 DS1820 1­WireTM Digital Thermometer FEATURES PIN ASSIGNMENT DALLAS DALLAS DS2434 DS1820 1 2 3 · Unique 1­WireTM interface requires only one port pin for communication · Multidrop capability simplifies distributed temperature sensing applications · Requires no external components · Can be powered from data line · Zero standby power required · Measures temperatures from ­55°C to +125°C in 0.5°C increments. Fahrenheit equivalent is ­67°F to +257°F in 0.9°F increments BOTTOM VIEW 1 2 3 · Temperature is read as a 9­bit digital value. · Converts temperature to digital word in 200 ms (typ.) · User­definable, tings nonvolatile temperature alarm set- DS1820 PR35 PACKAGE See Mech. Drawings Section GND DQ VDD NC NC NC NC NC NC VDD DQ 1 2 3 4 5 6 7 8 16 15 14 13 12 11 10 9 NC NC NC NC NC NC NC GND DS1820S 16­PIN SSOP See Mech. Drawings Section · Alarm search command identifies and addresses devices whose temperature is outside of programmed limits (temperature alarm condition) systems, consumer products, thermometers, or any thermally sensitive system PIN DESCRIPTION GND DQ VDD NC ­ ­ ­ ­ Ground Data In/Out Optional VDD No Connect · Applications include thermostatic controls, industrial DESCRIPTION The DS1820 Digital Thermometer provides 9­bit temperature readings which indicate the temperature of the device. Information is sent to/from the DS1820 over a 1­Wire interface, so that only one wire (and ground) needs to be connected from a central microprocessor to a DS1820. Power for reading, writing, and performing temperature conversions can be derived from the data line itself with no need for an external power source. Because each DS1820 contains a unique silicon serial number, multiple DS1820s can exist on the same 1­Wire bus. This allows for placing temperature sensors in many different places. Applications where this feature is useful include HVAC environmental controls, sensing temperatures inside buildings, equipment or machinery, and in process monitoring and control. ECopyright 1995 by Dallas Semiconductor Corporation. All Rights Reserved. For important information regarding patents and other intellectual property rights, please refer to Dallas Semiconductor data books. 021497 1/27 DS1820 DETAILED PIN DESCRIPTION PIN 16­PIN SSOP 9 8 7 PIN PR35 1 2 3 SYMBOL GND DQ VDD Ground. Data Input/Output pin. For 1­Wire operation: Open drain. (See "Parasite Power" section.) Optional VDD pin. See "Parasite Power" section for details of connection. DESCRIPTION DS1820S (16­pin SSOP): All pins not specified in this table are not to be connected. OVERVIEW The block diagram of Figure 1 shows the major components of the DS1820. The DS1820 has three main data components: 1) 64­bit lasered ROM, 2) temperature sensor, and 3) nonvolatile temperature alarm triggers TH and TL. The device derives its power from the 1­Wire communication line by storing energy on an internal capacitor during periods of time when the signal line is high and conti