LM66 Dual Output Internally Preset Thermostat
April 2000
LM66
Dual Output Internally Preset Thermostat
General Description
The LM66 is a precision low power thermostat. Two stable
temperature trip points (V
T1
and V
T2
) are generated by divid-
ing down the LM66 1.250V bandgap voltage reference using
a resistors divider network. The LM66 has two digital out-
puts. OUT1 goes LOW when the temperature exceeds T1
and goes HIGH when the the temperature goes below
(T1鈥揟
HYST
). Similarly, OUT2 goes LOW when the tempera-
ture exceeds T2 and goes HIGH when the temperature goes
below (T2鈥揟
HYST
). T
HYST
is an internally set 5藲C typical hys-
teresis.
The LM66 is currently available in an 8-lead small outline
package.
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Electronic System Protection
Features
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Digital outputs support TTL logic levels
Internal temperature sensor
2 internal comparators with hysteresis
Internal voltage reference
Currently available in 8-pin SO plastic package
Key Specifications
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Power Supply Voltage
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Power Supply Current
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V
REF
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Hysteresis Temperature
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Internal Temperature Sensor
Output Voltage
(+6.20 mV/藲C x T) +400 mV
鹵
3藲C (max)
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Temperature Trip Point Accuracy
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T1 set point
+73藲C
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T2 set point
+82藲C
2.7V to 10V
250 碌A(chǔ) (max)
1.250V
鹵
1.4% (max)
5藲C
Applications
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Microprocessor Thermal Management
Appliances
Portable Battery Powered 3.0V or 5V Systems
Fan Control
Industrial Process Control
HVAC Systems
Remote Temperature Sensing
Simplified Block Diagram and
Connection Diagram
Ordering Information
TABLE 1.
Order Number
NS Tackage
Number
Transport Media
LM66CIM-
RLSKB
M08A
Bulk Rail
LM66CIMX-
RLSKB
M08A
2500 Units Tape
& Reel
DS100854-1
Typical Application
DS100854-2
DS100854-3
漏 2000 National Semiconductor Corporation
DS100854
www.national.com
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