DS1722 Datasheet, PDF (1/14 Pages) Dallas Semiconductor – Digital Thermometer with SPI/3-Wire Interface

DS1722
Digital Thermometer with
SPI/3-Wire Interface
www.maxim-ic.com
FEATURES
PIN ASSIGNMENT
ƒ Temperature Measurements Require No
External Components
ƒ Measures Temperatures from -55°C to
V_DDD
1
8
V_DDA
V_DDD
1*
8
V_DDA
CE
2
7
SERMODE _CE
2
7 _SERMODE
+120°C. Fahrenheit Equivalent is -67°F to ^SCLK
3
6
SDI
+248°F
GND
4
5
SDO
SCLK ³
GND ⁴
6 _SDI
5
SDO
ƒ Thermometer Accuracy is ±2.0°C
ƒ Thermometer Resolution is Configurable
DS1722S
8-Pin SO (150mil)
DS1722U
8-PIN µMAX
from 8 to 12 bits (1.0°C to 0.0625°C
Resolution)
ƒ Data is Read From/Written to Via a Motorola
PIN DESCRIPTION
SERMODE
- Serial Interface Mode
Serial Peripheral Interface (SPI) or Standard
CE
- Chip Enable
3-Wire Serial Interface
ƒ Wide Analog Power Supply Range (2.65V -
SCLK
GND
- Serial Clock
- Ground
5.5V)
ƒ Separate Digital Supply Allows for 1.8V
V_DDA
SDO
- Analog Supply Voltage
- Serial Data Out
Logic
ƒ Available in an 8-Pin SO (150mil), 8-Pin
SDI
V_DDD
- Serial Data In
- Digital Supply Voltage
μMAX, and Flip-Chip Package
DESCRIPTION
The DS1722 Digital Thermometer and Thermostat with SPI/3-Wire Interface provides temperature
readings which indicate the temperature of the device. No additional components are required; the device
is truly a temperature-to-digital converter. Temperature readings are communicated from the DS1722
over a Motorola SPI interface or a standard 3-wire serial interface. The choice of interface standard is
selectable by the user.
For applications that require greater temperature resolution, the user can adjust the readout resolution
from 8 to 12 bits. This is particularly useful in applications where thermal runaway conditions must be
detected quickly.
For application flexibility, the DS1722 features a wide analog supply rail of 2.65V - 5.5V. A separate
digital supply allows a range of 1.8V to 5.5V.
The DS1722 is available in an 8-pin SO (150mil), 8-pin μMAX, and flip-chip package.
Applications for the DS1722 include personal computers/servers/workstations, cellular telephones, office
equipment, or any thermally-sensitive system.
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