DS1722U Maxim Integrated Products, DS1722U Datasheet - Page 4
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DS1722U
Manufacturer Part Number
DS1722U
Description
IC THERMOMETER DIG 3-WIRE 8-USOP
Manufacturer
Maxim Integrated Products
Datasheet
1.DS1722STR.pdf
(14 pages)
Specifications of DS1722U
Function
Thermometer, Thermostat
Topology
ADC, Register Bank
Sensor Type
Internal
Sensing Temperature
-55°C ~ 120°C
Output Type
SPI™
Output Alarm
No
Output Fan
No
Voltage - Supply
2.65 V ~ 5.5 V
Operating Temperature
-55°C ~ 120°C
Mounting Type
Surface Mount
Package / Case
8-MSOP, Micro8™, 8-uMAX, 8-uSOP,
Full Temp Accuracy
+/- 3 C
Digital Output - Bus Interface
Serial (3-Wire, SPI)
Digital Output - Number Of Bits
12 bit
Maximum Operating Temperature
+ 125 C
Minimum Operating Temperature
- 55 C
Lead Free Status / RoHS Status
Contains lead / RoHS non-compliant
Available stocks
Company
Part Number
Manufacturer
Quantity
Price
Part Number:
DS1722U
Manufacturer:
MAXIM/美信
Quantity:
20 000
Company:
Part Number:
DS1722U+
Manufacturer:
Maxim
Quantity:
750
Part Number:
DS1722U+
Manufacturer:
MAXIM/美信
Quantity:
20 000
Part Number:
DS1722U+TR
Manufacturer:
MAXIM/美信
Quantity:
20 000
DS1722
DS1722 FUNCTIONAL BLOCK DIAGRAM Figure 1
OPERATION-Measuring Temperature
The core of DS1722 functionality is its direct-to-digital temperature sensor. The DS1722 measures
temperature through the use of an on-chip temperature measurement technique with an operating range
from -55° to +120°C. The device powers up in a power-conserving shutdown mode. After power-up, the
DS1722 may be placed in a continuous conversion mode or in a one-shot conversion mode. In the
continuous conversion mode, the device continuously computes the temperature and stores the most
recent result in the temperature register at addresses 01h (LSB) and 02h (MSB). In the one-shot
conversion mode, the DS1722 performs one temperature conversion and then returns to the shutdown
mode, storing temperature in the temperature register. Details on how to change the setting after power-
up are contained in the “OPERATION-Programming” section.
The resolution of the temperature conversion is configurable (8, 9, 10, 11, or 12 bits), with 9-bit readings
the default state. This equates to a temperature resolution of 1.0°C, 0.5°C, 0.25°C, 0.125°C, or 0.0625°C.
Following each conversion, thermal data is stored in the thermometer register in two’s complement
format; the information can be retrieved over the SPI or 3-wire interface with the address set to the
temperature register, 01h (LSB) and then 02h (MSB). Table 3 describes the exact relationship of output
data to measured temperature. The table assumes the DS1722 is configured for 12-bit resolution; if the
device is configured in a lower resolution mode, those bits will contain 0s. The data is transmitted
serially over the digital interface, MSb first for SPI communication and LSb first for 3-wire
communication. The MSb of the temperature register contains the “sign” (S) bit, denoting whether the
temperature is positive or negative. For Fahrenheit usage, a lookup table or conversion routine must be
used.
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