Rainbow Electronics LM70 - Manual

LM70
SPI/MICROWIRE 10-Bit plus Sign Digital Temperature
Sensor
General Description
The LM70 is a temperature sensor, Delta-Sigma analog-to-
digital converter with an SPI and MICROWIRE compatible
interface available in LLP and MSOP 8-pin packages. The
host can query the LM70 at any time to read temperature. A
shutdown mode decreases power consumption to less than
10 µA. This mode is useful in systems where low average
power consumption is critical.
The LM70 has 10-bit plus sign temperature resolution
(0.25˚C per LSB) while operating over a temperature range
of −55˚C to +150˚C.
The LM70’s 2.65V 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.
Applications
n System Thermal Management
n Personal Computers
n Disk Drives
n Office Electronics
n Electronic Test Equipment
Features
n 0.25˚C temperature resolution.
n Shutdown mode conserves power between temperature
reading
n SPI and MICROWIRE Bus interface
n MSOP-8 and LLP-8 packages save space
Key Specifications
j Supply Voltage 2.65V to 5.5V
j Supply Current operating 260 µA (typ)
490 µA (max)
shutdown 12 µA (typ)
j Temperature
Accuracy
−40˚C to 85˚C ± 2˚C(max)
−10˚C to 65˚C +1.5/−2˚C(max)
−55˚C to 125˚C +3/−2˚C(max)
−55˚C to 150˚C +3.5/−2˚C(max)
Simplified Block Diagram
10122301
February 2005
LM70
SPI/MICROWIRE
™
10-Bit
plus
Sign
Digital
T
emperature
Sensor
© 2005 National Semiconductor Corporation DS101223 www.national.com