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.
n
Electronic System Protection
Features
n
n
n
n
n
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
j
Power Supply Voltage
j
Power Supply Current
j
V
REF
j
Hysteresis Temperature
j
Internal Temperature Sensor
2.7V to 10V
250 碌A(chǔ) (max)
1.250V
鹵
1.4% (max)
5藲C
Applications
n
n
n
n
n
n
n
Microprocessor Thermal Management
Appliances
Portable Battery Powered 3.0V or 5V Systems
Fan Control
Industrial Process Control
HVAC Systems
Remote Temperature Sensing
Output Voltage
(+6.20 mV/藲C x T) +400 mV
鹵
3藲C (max)
n
Temperature Trip Point Accuracy
n
T1 set point
+73藲C
n
T2 set point
+82藲C
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
Powered by ICminer.com Electronic-Library Service CopyRight 2003
1
2
3
4
5
