LM74 SPI/MICROWIRE 12-Bit Plus Sign Temperature Sensor
April 2003
LM74
SPI/MICROWIRE
™
12-Bit Plus Sign Temperature Sensor
General Description
The LM74 is a temperature sensor, Delta-Sigma analog-to-
digital converter with an SPI and MICROWIRE compatible
interface. The host can query the LM74 at any time to read
temperature. A shutdown mode decreases power consump-
tion to less than 10 µA. This mode is useful in systems where
low average power consumption is critical.
The LM74 has 12-bit plus sign temperature resolution
(0.0625˚C per LSB) while operating over a temperature
range of −55˚C to +150˚C.
The LM74’s 3.0V to 5.5V supply voltage range, low supply
current and simple SPI interface make it ideal for a wide
range of applications. These include thermal management
and protection applications in hard disk drives, printers, elec-
tronic test equipment, and office electronics. The LM74 is
available in the SO-8 package as well as an 5-Bump micro
SMD package.
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Electronic Test Equipment
Features
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0.0625˚C temperature resolution.
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Shutdown mode conserves power between temperature
reading
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SPI and MICROWIRE Bus interface
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5-Bump micro SMD package saves space
Key Specifications
j
Supply Voltage
j
Supply Current
3.0V or 2.65V to
5.5V
operating
shutdown
265µA (typ)
520µA (max)
3µA (typ)
j
Temperature
Applications
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System Thermal Management
Personal Computers
Disk Drives
Office Electronics
Accuracy
−10˚C to 65˚C
−25˚C to 110˚C
−55˚C to 125˚C
±
1.25˚C(max)
±
2.1˚C(max)
±
3˚C(max)
Simplified Block Diagram
10090901
MICROWIRE
®
is a registered trademark of National Semiconductor Corporation.
TRI-STATE
®
is a registered trademark of National Semiconductor Corporation.
© 2003 National Semiconductor Corporation
DS100909
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