LM26_07 Datasheet, PDF (1/10 Pages) National Semiconductor (TI) – SOT-23, ±3°C Accurate, Factory Preset Thermostat

February 2007
LM26
SOT-23, ±3°C Accurate, Factory Preset Thermostat
General Description
The LM26 is a precision, single digital-output, low-power ther-
mostat comprised of an internal reference, DAC, temperature
sensor and comparator. Utilizing factory programming, it can
be manufactured with different trip points as well as different
digital output functionality. The trip point (T_OS) can be preset
at the factory to any temperature in the range of −55°C to
+110°C in 1°C increments. The LM26 has one digital output
(OS/OS/US/US), one digital input (HYST) and one analog
output (V_TEMP). The digital output stage can be preset as ei-
ther open-drain or push-pull. In addition, it can be factory
programmed to be active HIGH or LOW. The digital output
can be factory programmed to indicate an over temperature
shutdown event (OS or OS) or an under temperature shut-
down event (US or US). When preset as an overtemperature
shutdown (OS) it will go LOW to indicate that the die temper-
ature is over the internally preset T_OS and go HIGH when the
temperature goes below (T_OS–T_HYST). Similarly, when pre-
programmed as an undertemperature shutdown (US) it will
go HIGH to indicate that the temperature is below T_US and go
LOW when the temperature is above (T_US+T_HYST). The typical
hysteresis, T_HYST, can be set to 2°C or 10°C and is controlled
by the state of the HYST pin. A V_TEMP analog output provides
a voltage that is proportional to temperature and has a
−10.82mV/°C output slope.
Available parts are detailed in the ordering information. For
other part options, contact a National Semiconductor Distrib-
utor or Sales Representative for information on minimum
order qualification. The LM26 is currently available in a 5-lead
SOT-23 package.
Applications
■ ^{Microprocessor Thermal Management}
■ ^Appliances
■ ^{Portable Battery Powered Systems}
■ ^{Fan Control}
■ ^{Industrial Process Control}
■ ^{HVAC Systems}
■ ^{Remote Temperature Sensing}
■ ^{Electronic System Protection}
Features
■ ^{Internal comparator with pin programmable 2°C or 10°C}
hysteresis
■ ^{No external components required}
■ ^{Open Drain or push-pull digital output; supports CMOS}
logic levels
■ ^{Internal temperature sensor with V}_TEMP ^{output pin}
■ ^V_TEMP ^{output allows after-assembly system testing}
■ ^{Internal voltage reference and DAC for trip-point setting}
■ ^{Currently available in 5-pin SOT-23 plastic package}
■ ^{Excellent power supply noise rejection}
■ ^{UL Recognized Component}
Key Specifications
■ Power Supply Voltage
■ Power Supply Current
■ Hysteresis Temperature
2.7V to 5.5V
40µA(max)
20µA(typ)
2°C or 10°C(typ)
Temperature Trip Point Accuracy
Temperature Range
−55°C to +110°C
LM26CIM
±3°C (max)
+120°C
±4°C (max)
LM26CIM5-TPA Simplified Block Diagram and Connection Diagram
The LM26CIM5-TPA has a fixed trip point of 85°C.
For other trip point and output function availability,
please see ordering information or contact National Semiconductor.
10132301
© 2007 National Semiconductor Corporation 101323
www.national.com