LM75CIM-5 National Semiconductor, LM75CIM-5 Datasheet - Page 6

• Manufacturer Part Number: LM75CIM-5
• Description: Temperature Sensor IC
• Manufacturer: National Semiconductor

Specifications of LM75CIM-5

• Mounting Type: Surface Mount
• Supply Voltage Min: 3V
• Operating Temperature Max: 125°C
• Peak Reflow Compatible (260 C): No
• Ic Function: Temperature Sensor IC
• Supply Voltage Max: 5.5V
• Leaded Process Compatible: No
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

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Typical Performance Characteristics
Static Quiescent Current vs
Temperature
1.0 Functional Description
The LM75 temperature sensor incorporates a band-gap type
temperature
Analog-to-Digital Converter). The temperature data output of
the LM75 is available at all times via the I
sion is in progress, it will be stopped and restarted after the
read. A digital comparator is also incorporated that compares
a series of readings, the number of which is user-selectable,
to user-programmable setpoint and hysteresis values. The
comparator trips the O.S. output line, which is programmable
for mode and polarity.
1.1 O.S. OUTPUT, T
In Comparator mode the O.S. Output behaves like a thermo-
stat. The output becomes active when temperature exceeds
the T
ture drops below the T
put can be used to turn a cooling fan on, initiate an emer-
gency system shutdown, or reduce system clock speed.
Shutdown mode does not reset O.S. state in a comparator
mode.
In Interrupt mode exceeding T
O.S. will remain active indefinitely until reset by reading any
register via the I
by crossing T
Temperature going below T
indefinitely until being reset by a read. Placing the LM75 in
shutdown mode also resets the O.S. Output.
OS
limit, and leaves the active state when the tempera-
OS
sensor
, then reset, it can be activated again only by
2
C interface. Once O.S. has been activated
OS
HYST
AND T
and
HYST
DS012658-16
limit. In this mode the O.S. out-
OS
HYST
9-bit
. Again, it will remain active
also makes O.S. active but
LIMITS
ADC
2
C bus. If a conver-
Dynamic Quiescent Current vs
Temperature
(Delta-Sigma
6
1.2 POWER UP AND POWER DOWN
The LM75 always powers up in a known state. The power up
default conditions are:
1. Comparator mode
2. T
3. T
4. O.S. active low
5. Pointer = “00”
If the LM75 is not connected to the I
will act as a stand-alone thermostat with the above tempera-
ture settings.
When the supply voltage is less than about 1.7V, the LM75 is
considered powered down. As the supply voltage rises
above the nominal 1.7V power up threshold, the internal reg-
isters are reset to the power up default values listed above.
1.3 I
The LM75 operates as a slave on the I
line is an input (no clock is generated by the LM75) and the
SDA line is a bi-directional serial data path. According to I
bus specifications, the LM75 has a 7-bit slave address. The
four most significant bits of the slave address are hard wired
inside the LM75 and are “1001”. The three least significant
bits of the address are assigned to pins A2–A0, and are set
by connecting these pins to ground for a low, (0); or to +V
for a high, (1).
Therefore, the complete slave address is:
MSB
1
2
DS012658-17
OS
HYST
C BUS INTERFACE
= 80˚C
= 75˚C
0
0
Accuracy vs Temperature
1
A2
2
C bus on power up, it
2
C bus, so the SCL
A1
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LSB
A0
2
C
S