DS1822-PAR Datasheet, PDF (1/19 Pages) Dallas Semiconductor – Econo 1-Wire Parasite-Power Digital Thermometer

DS1822-PAR
Econo 1-Wire^® Parasite-Power
Digital Thermometer
www.dalsemi.com
FEATURES
• Unique 1-wire interface requires only one
port pin for communication
• Derives power from data line (“parasite
power”)—does not need a local power supply
• Multi-drop capability simplifies distributed
temperature sensing applications
• Requires no external components
• ±2.0°C accuracy from –10°C to +85°C
• Measures temperatures from –55°C to
+100°C (–67°F to +212°F)
• Thermometer resolution is user-selectable
from 9 to 12 bits
• Converts temperature to 12-bit digital word in
750 ms (max.)
• User–definable temperature alarm settings
• Alarm search command identifies and
addresses devices whose temperature is
outside of programmed limits (temperature
alarm condition)
• Software compatible with the DS18B20-PAR
• Ideal for use in remote sensing applications
(e.g., temperature probes) that do not have a
local power source
PIN ASSIGNMENT
DALLAS
1822P
123
123
(BOTTOM VIEW)
TO-92
(DS1822-PAR)
PIN DESCRIPTION
GND - Ground
DQ - Data In/Out
NC - No Connect
DESCRIPTION
The DS1822-PAR digital thermometer provides 9 to 12–bit centigrade temperature measurements and has
an alarm function with nonvolatile user-programmable upper and lower trigger points. The DS1822-PAR
does not need an external power supply because it derives power directly from the data line (“parasite
power”). The DS1822-PAR communicates over a 1-wire bus, which 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 +100°C and is accurate to ±2.0°C over a range of –10°C to +85°C.
Each DS1822-PAR has a unique 64-bit identification code, which allows multiple DS1822-PARs to
function on the same 1–wire bus; thus, it is simple to use one microprocessor to control many
DS1822-PARs 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.
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