Internal comparator with pin programmable 2°C or 10°C hysteresis
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No external components required
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Open Drain or push-pull digital output; supports CMOS logic levels
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Internal temperature sensor with VTEMP output pin
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VTEMP output allows after-assembly system testing
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Internal voltage reference and DAC for trip-point setting
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Currently available in 5-pin SOT-23 plastic package
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Excellent power supply noise rejection
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UL Recognized Component
Description
The LM26 is a precision, single digital-output, low-power thermostat 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 (TOS) 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 (VTEMP). The digital output stage can be preset as either 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 shutdown event (US or
^US). When preset as an overtemperature shutdown (
^OS) it will go LOW to indicate that the die temperature is over the internally preset TOS and go HIGH when the temperature goes below (TOS–THYST). Similarly, when preprogrammed as an undertemperature shutdown (US) it will go HIGH to indicate that the temperature is
below TUS and go LOW when the temperature is above (TUS+THYST). The typical hysteresis, THYST, can be set to 2°C or 10°C and is controlled by the state of the HYST pin. A VTEMP 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 Distributor
or Sales Representative for information on minimum order qualification. The LM26 is currently available in a 5-lead SOT-23
package.
Note: The Early Failure Rates (EFR) were calculated as point estimate PPM based on rejects and sample size for EFR.
The Long Term Failure Rates were calculated
at 60% confidence using the Arrhenius equation at 0.7eV activation energy and derating the assumed stress
temperature of 150°C to an application temperature of 55°C.
For more information on Reliability Metrics, please click here.
LM26LV
