DS1820 Datasheet, PDF (1/27 Pages) Dallas Semiconductor – 1-Wire Digital Thermometer

DS1820
DS1820
1–Wire^TM Digital Thermometer
FEATURES
• Unique 1–Wire^TM 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
• Temperature is read as a 9–bit digital value.
• Converts temperature to digital word in 200 ms (typ.)
• User–definable, nonvolatile temperature alarm set-
tings
• Alarm search command identifies and addresses
devices whose temperature is outside of pro-
grammed limits (temperature alarm condition)
• Applications include thermostatic controls, industrial
systems, consumer products, thermometers, or any
thermally sensitive system
PIN ASSIGNMENT
DDAALLLALSAS
DDSS18224034
1 23
1 23
BOTTOM VIEW
DS1820
PR35 PACKAGE
See Mech. Drawings
Section
NC
1
NC
2
NC
3
NC
4
NC
5
NC
6
VDD
7
DQ
8
16
NC
15
NC
14
NC
13
NC
12
NC
11
NC
10
NC
9
GND
DS1820S
16–PIN SSOP
See Mech. Drawings
Section
PIN DESCRIPTION
GND
– Ground
DQ
– Data In/Out
V_DD
– Optional V_DD
NC
– No Connect
DESCRIPTION
The DS1820 Digital Thermometer provides 9–bit tem-
perature readings which indicate the temperature of the
device.
Information is sent to/from the DS1820 over a 1–Wire
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
1–Wire bus. This allows for placing temperature sen-
sors 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.
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