19-4385; Rev 0; 3/09
Digital Temperature Sensor and Thermal
Watchdog with 2-Wire Interface
The LM75 temperature sensor includes a delta-sigma
analog-to-digital converter, and a digital overtemperature detector. The host can query the LM75 through its
I 2 C interface to read temperature at any time. The
open-drain overtemperature output (OS) sinks current
when the programmable temperature limit is exceeded.
The OS output operates in either of two modes, comparator or interrupt. The host controls the temperature
at which the alarm is asserted (TOS) and the hysteresis
temperature below which the alarm condition is not
valid (THYST). Also, the LM75’s TOS and THYST registers can be read by the host. The address of the LM75
is set with three pins to allow multiple devices to work
on the same bus. Power-up is in comparator mode, with
defaults of TOS = +80°C and THYST = +75°C. The 3.0V
to 5.5V supply voltage range, low supply current, and
I2C interface make the LM75 ideal for many applications in thermal management and protection.
Applications
Features
o SO (SOP) and µMAX® (µSOP) Packages
o I2C Bus Interface
o Separate Open-Drain OS Output Operates as
Interrupt or Comparator/Thermostat Input
o Register Readback Capability
o Power-Up Defaults Permit Stand-Alone Operation
as a Thermostat
o 3.0V to 5.5V Supply Voltage
o Low Operating Supply Current 250µA (typ), 1mA
(max)
o 4µA (typ) Shutdown Mode Minimizes Power
Consumption
o Up to Eight LM75s Can Be Connected to a Single
Bus
o Pin- and/or Register-Compatible with ImprovedPerformance Maxim Sensors Including MAX7500,
MAX6625, MAX6626, DS75LV, and DS7505
Thermal System Management
Thermal Protection
Test Equipment
Computers and Office Electronics
Functional Diagram
+VS = 3.0V to 5.5V
8
3
16
SILICON
BANDGAP
TEMPERATURE
SENSOR
µMAX is a registered trademark of Maxim Integrated Products, Inc.
9-BIT DELTASIGMA ADC
16
TOS SET POINT
REGISTER
Pin Configuration
TOP VIEW
SDA
1
SCL
2
OS
GND
3
4
POINTER
REGISTER
CONFIGURATION
REGISTER
+
8
LM75
A0
THYST SET
POINT REGISTER
+VS
7
OS
SET POINT
COMPARATOR W/
HYSTERESIS
6
5
8
A1
A2
16
8
16
16
1
7
A0
6
A1
5
A2
SDA
2-WIRE INTERFACE
2
SCL
4
μMAX (μSOP), SO
Ordering Information/Selector Guide
PIN-PACKAGE
PKG
SUPPLY VOLTAGE (V)
TOP MARK
LM75BIM-3+
PART
8 SO (SOP)
Bulk
3.3
LM75BIM-3
LM75BIMX-3+
8 SO (SOP)
T&R
3.3
LM75BIM-3
LM75BIMM-3+
8 µMAX (µSOP)
Bulk
3.3
T01B
LM75BIMMX-3+
8 µMAX (µSOP)
T&R
3.3
T01B
LM75BIM-5+
8 SO (SOP)
Bulk
5.0
LM75BIM-5
LM75BIMX-5+
8 SO (SOP)
T&R
5.0
LM75BIM-5
LM75BIMM-5+
8 µMAX (µSOP)
Bulk
5.0
T00B
LM75BIMMX-5+
8 µMAX (µSOP)
T&R
5.0
T00B
Note: Devices are specified over the -55°C to +125°C temperature range and include I2C noise filter.
+Denotes a lead(Pb)-free/RoHS-compliant package.
T&R = Tape and reel.
________________________________________________________________ Maxim Integrated Products
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.
1
LM75
General Description
