DS1822
Econo 1-Wire Digital
Thermometer
PIN ASSIGNMENT
DALLAS
1822
1 2 3
NC
NC
V
DD
DQ
1
8
FEATURES
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Unique 1-Wire
®
interface requires only one
port pin for communication.
Each device has a unique 64-bit serial code
stored in an on-board ROM.
Multidrop capability simplifies distributed
temperature-sensing applications.
Requires no external components.
Can be powered from data line. Power supply
range is 3.0V to 5.5V.
Measures temperatures from -55°C to +125°C
(-67°F to +257°F).
±2.0°C
accuracy from -10°C to +85°C.
Thermometer resolution is user-selectable
from 9 to 12 bits.
Converts temperature to 12-bit digital word in
750ms (max.)
User-definable nonvolatile (NV) alarm
settings.
Alarm search command identifies and
addresses devices whose temperature is
outside of programmed limits (temperature
alarm condition).
Software compatible with the DS18B20.
Applications include thermostatic controls,
industrial systems, consumer products,
thermometers, or any thermally sensitive
system.
NC
NC
NC
GND
DS1822
2
3
4
7
6
5
8-Pin 150mil SO
(DS1822Z)
(BOTTOM VIEW)
TO-92
(DS1822)
PIN DESCRIPTION
GND
DQ
V
DD
NC
- Ground
- Data In/Out
- Power Supply Voltage
- No Connect
DESCRIPTION
The DS1822 digital thermometer provides 9- to 12-bit centigrade temperature measurements and has an
alarm function with NV user-programmable upper and lower trigger points. The DS1822 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
±2.0°C
over the range of –10°C to +85°C. In addition, the DS1822 can derive power directly from the
data line (“parasite power”), eliminating the need for an external power supply.
Each DS1822 has a unique 64-bit serial code, which allows multiple DS1822s to function on the 1-Wire
bus; thus, it is simple to use one microprocessor to control many DS1822s 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.
1-Wire is a registered trademark of Dallas Semiconductor.
1 of 20
GND
DQ
V
DD
1 2
3
061002
DALLAS [ DALLAS SEMICONDUCTOR ]
