LM26

Features:

`Internal comparator with pin programmable 2 or 10 hysteresis
`No external components required
`Open Drain or push-pull digital output; supports CMOS logic levels
`Internal temperature sensor with VTEMP output pin
`VTEMP 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



Application

·Microprocessor Thermal Management
·Appliances
·Portable Battery Powered Systems
·Fan Control
·Industrial Process Control
·HVAC Systems
·Remote Temperature Sensing
·Electronic System Protection

Pinout




Specifications

Input Voltage                                              6.0V
Input Current at any pin (Note 2)               5mA
Package Input Current(Note 2)                 20mA
Package Dissipation at T_A = 25
(Note 3)                                                  500mW
Soldering Information
SOT23 Package
Vapor Phase (60 seconds)                         215
Infrared (15 seconds)                                220
Storage Temperature                -65 to + 150
ESD Susceptibility (Note 4)
Human Body Model                                   2500V
Machine Model                                            250V

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 to +110 in 1 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 (T_OST_HYST). 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 (T_US+T_HYST). The typical hysteresis, THYST, can be set to 2 or 10 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/ 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.