Rainbow Electronics LM26 User Manual
LM26
LM26 SOT-23,
June 2004
SOT-23,
±
3˚C Accurate, Factory Preset Thermostat
General 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 (T
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
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 TOSand go
HIGH when the temperature goes below (T
larly, when preprogrammed as an undertemperature shutdown (US) it will go HIGH to indicate that the temperature is
below T
(T
US+THYST
2˚C or 10˚C and is controlled by the state of the HYST pin. A
V
TEMP
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.
and go LOW when the temperature is above
US
). The typical hysteresis, T
analog output provides a voltage that is proportional
). The digital output stage can be
TEMP
OS–THYST
, can be set to
HYST
OS
). Simi-
Applications
n Microprocessor Thermal Management
n Appliances
n Portable Battery Powered Systems
n Fan Control
n Industrial Process Control
n HVAC Systems
n Remote Temperature Sensing
n Electronic System Protection
)
Features
n Internal comparator with pin programmable 2˚C or 10˚C
hysteresis
n No external components required
n Open Drain or push-pull digital output; supports CMOS
logic levels
n Internal temperature sensor with V
n V
n Internal voltage reference and DAC for trip-point setting
n Currently available in 5-pin SOT-23 plastic package
n Excellent power supply noise rejection
output allows after-assembly system testing
TEMP
TEMP
output pin
Key Specifications
j
Power Supply Voltage 2.7V to 5.5V
j
Power Supply Current 40µA(max)
j
Hysteresis Temperature 2˚C or 10˚C(typ)
Temperature Trip Point Accuracy
Temperature Range LM26CIM
−55˚C to +110˚C
+120˚C
±
3˚C (max)
±
4˚C (max)
±
3˚C Accurate, Factory Preset Thermostat
20µA(typ)
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.
© 2004 National Semiconductor Corporation DS101323 www.national.com
10132301
Ordering Information
LM26
For more detailed information on the suffix meaning see the part number template at the end of the Electrical Characteristics Section. Contact National Semiconductor for other set points and output options.
Order Number
Top Mark
LM26CIM5-KLA LM26CIM5X-KLA TKLA MA05B 23˚C Open Drain OS
LM26CIM5-NPA LM26CIM5X-NPA TNPA MA05B 45˚C Open Drain OS
LM26CIM5-RPA LM26CIM5X-RPA TRPA MA05B 65˚C Open Drain OS
LM26CIM5-SHA LM26CIM5X-SHA TSHA MA05B 70˚C Open Drain OS
LM26CIM5-SPA LM26CIM5X-SPA TSPA MA05B 75˚C Open Drain OS
LM26CIM5-TPA LM26CIM5X-TPA TTPA MA05B 85˚C Open Drain OS
LM26CIM5-VHA LM26CIM5X-VHA TVHA MA05B 90˚C Open Drain OS
LM26CIM5-VPA LM26CIM5X-VPA TVPA MA05B 95˚C Open Drain OS
LM26CIM5-XHA LM26CIM5X-XHA TXHA MA05B 100˚C Open Drain OS
LM26CIM5-XPA LM26CIM5X-XPA TXPA MA05B 105˚C Open Drain OS
LM26CIM5-YHA LM26CIM5X-YHA TYHA MA05B 110˚C Open Drain OS
LM26CIM5-YPA LM26CIM5X-YPA TYPA MA05B 115˚C Open Drain OS
LM26CIM5-ZHA LM26CIM5X-ZHA TZHA MA05B 120˚C Open Drain OS
NS Package
Number Trip Point Setting Output FunctionBulk Rail 3000 Units in Tape & Reel
Connection Diagram
10132302
Pin Description
Pin
Number
1 HYST Hysteresis control, digital input GND for 10˚C or V+for 2˚C
2 GND Ground, connected to the back side of
3V
4V+Supply input 2.7V to 5.5V with a 0.1µF bypass capacitor. For
5OS
Note: pin 5 functionality and trip point setting are programmed during LM26 manufacture.
Pin
Name
the die through lead frame.
TEMP
OS Overtemperature Shutdown push-pull
US
US Undertemperature Shutdown push-pull
Analog output voltage proportional to
temperature
Overtemperature Shutdown open-drain
active low thermostat digital output
active high thermostat digital output
Undertemperature Shutdown open-drain
active low thermostat digital output
active high thermostat digital output
Function Connection
System GND
Leave floating or connect to a high impedance
node.
PSRR information see Section Titled NOISE
CONSIDERATIONS.
Controller interrupt, system or power supply
shutdown; pull-up resistor ≥ 10kΩ
Controller interrupt, system or power supply
shutdown
System or power supply shutdown; pull-up
resistor ≥ 10kΩ
System or power supply shutdown
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LM26
Absolute Maximum Ratings (Note 1)
Input Voltage 6.0V
Input Current at any pin (Note 2) 5mA
ESD Susceptibility (Note 4)
Human Body Model
Machine Model
2500V
Package Input Current(Note 2) 20mA
Package Dissipation at T
= 25˚C
A
(Note 3) 500mW
Soldering Information
SOT23 Package
Vapor Phase (60 seconds)
Infrared (15 seconds)
215˚C
220˚C
Operating Ratings(Note 1)
Specified Temperature Range T
LM26CIM −55˚C ≤ TA≤ +125˚C
Positive Supply Voltage (V
Maximum V
OUT
+
) +2.7V to +5.5V
MIN
≤ TA≤ T
Storage Temperature −65˚C to + 150˚C
LM26 Electrical Characteristics
The following specifications apply for V+= 2.7VDCto 5.5VDC, and V
face limits apply for T
A=TJ=TMIN
to T
; all other limits TA=TJ= 25˚C unless otherwise specified.
MAX
Symbol Parameter Conditions (Note 6) Limits (Limits)
Temperature Sensor
Trip Point Accuracy (Includes
V
, DAC, Comparator Offset,
REF
and Temperature Sensitivity
-55˚C ≤ T
+120˚C
≤ +110˚C
A
errors)
Trip Point Hysteresis HYST = GND 11 ˚C
+
V
Output Temperature
TEMP
HYST = V
Sensitivity
Temperature Sensitivity
V
TEMP
Error to Equation:
= (−3.479x10−6x(T−30)2)
V
O
+ (−1.082x10−2x(T−30)) +
1.8015V
V
Load Regulation −1µA ≤ IL≤ 0 0.070 mV
TEMP
V
Line Regulation +2.7V ≤ V+≤ +5.5V,
TEMP
−30˚C ≤ T
2.7V ≤ V
−55˚C ≤ T
4.5V ≤ V
A
+
≤ 5.5V
A
+
≤ 5.5V
≤ 120˚C,
≤ 120˚C,
TA= 30˚C
0 ≤ I
≤ +40µA 0.7 mV (max)
L
−30˚C ≤ T
≤
A
+120˚C
I
S
Supply Current 16 20
Digital Output and Input
I
OUT(“1”)
Logical “1” Output Leakage
V+= +5.0V 0.001 1 µA (max)
Current (Note 9)
V
OUT(“0”)
V
OUT(“1”)
Logical “0” Output Voltage I
Logical “1” Push-Pull Output
Voltage
V
IH
HYST Input Logical ”1“ Threshold
= +1.2mA and
OUT
+
≥2.7V;
V
= +3.2mA and
I
OUT
+
≥4.5V; (Note 8)
V
I
SOURCE
V
I
SOURCE
V
+
≥ 2.7V
+
≥4.5V
= 500µA,
= 800µA,
Voltage
V
IL
HYST Input Logical ”0“ Threshold
Voltage
load current = 0µA unless otherwise specified. Bold-
TEMP
Typical LM26CIM Units
(Note 7)
±
3 ˚C (max)
±
4 ˚C (max)
2˚C
−10.82 mV/˚C
±
3 ˚C (max)
±
3 ˚C (max)
±
2.5 ˚C (max)
−0.2 mV/V
40
0.4 V (max)
+
0.8xV
+
V
− 1.5 V (min)
+
0.8xV
+
0.2xV
µA (max)
µA (max)
V (min)
V (min)
V (max)
250V
MAX
+5.5V
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