National Semiconductor LM26 Technical data

LM26
SOT-23, ±3°C Accurate, Factory Preset Thermostat

Fan Control

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 (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

/US/US), one digital input (HYST) and one analog

(OS/OS
output (V
ther 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–T
programmed 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+T
hysteresis, T
by the state of the HYST pin. A V
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.

). The digital output stage can be preset as ei-

TEMP

). Similarly, when pre-

HYST

). The typical

, can be set to 2°C or 10°C and is controlled

HYST

TEMP

HYST

analog output provides

Applications

Microprocessor Thermal Management

■

Appliances

■

Portable Battery Powered Systems

■

■

Industrial Process Control

■

HVAC Systems

■

Remote Temperature Sensing

■

Electronic System Protection

■

Features

Internal comparator with pin programmable 2°C or 10°C

■

hysteresis
No external components required

■

Open Drain or push-pull digital output; supports CMOS

■

logic levels
Internal temperature sensor with V

■

V

■

■

■

■

■

output allows after-assembly system testing

TEMP

Internal voltage reference and DAC for trip-point setting
Currently available in 5-pin SOT-23 plastic package
Excellent power supply noise rejection
UL Recognized Component

TEMP

output pin

Key Specifications

■ Power Supply Voltage 2.7V to 5.5V

■ Power Supply Current

■ Hysteresis Temperature 2°C or 10°C(typ)

Temperature Trip Point Accuracy

Temperature Range LM26CIM

−55°C to +110°C ±3°C (max)

+120°C ±4°C (max)

LM26 SOT-23, ±3°C Accurate, Factory Preset Thermostat

July 31, 2008

40µA(max)

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.

© 2008 National Semiconductor Corporation 101323 www.national.com

10132301

LM26

Ordering Information

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

Bulk Rail 3000 Units in Tape &

Reel

LM26CIM5-DPB LM26CIM5X-DPB TDPB MA05B −25°C Open Drain US

LM26CIM5-HHD LM26CIM5X-HHD THHD MA05B 0°C Push Pull US

LM26CIM5-NPA LM26CIM5X-NPA TNPA MA05B 45°C Open Drain OS

LM26CIM5-PHA LM26CIM5X-PHA TPHA MA05B 50°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

Top Mark

NS Package

Number

Trip Point Setting Output Function

Connection Diagram

10132302

Pin Descriptions

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 the die

3 V

4 V

5 OS Overtemperature Shutdown open-drain active

Note: pin 5 functionality and trip point setting are programmed during LM26 manufacture.

Pin

Name

through lead frame.

Analog output voltage proportional to

TEMP

temperature

+

Supply input 2.7V to 5.5V with a 0.1µF bypass capacitor. For PSRR

low thermostat digital output

OS Overtemperature Shutdown push-pull active

high thermostat digital output

US Undertemperature Shutdown open-drain active

low thermostat digital output

US Undertemperature Shutdown push-pull active

high thermostat digital output

Function Connection

System GND

Leave floating or connect to a high impedance node.

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

www.national.com 2

LM26

Absolute Maximum Ratings (Note 1)

Input Voltage 6.0V
Input Current at any pin (Note 2) 5mA

Storage Temperature −65°C to + 150°C
ESD Susceptibility (Note 4)

Human Body Model
Machine Model

Package Input Current(Note 2) 20mA
Package Dissipation at TA = 25°C

 (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

LM26CIM

Positive Supply Voltage (V+)

Maximum V

OUT

T

≤ TA ≤ T

MIN

−55°C ≤ TA ≤ +125°C

+2.7V to +5.5V

LM26 Electrical Characteristics

The following specifications apply for V+ = 2.7VDC to 5.5VDC, and V

limits apply for TA = TJ = T

MIN

to T

; all other limits TA = TJ = 25°C unless otherwise specified.

MAX

Typical LM26CIM Units

Symbol Parameter Conditions

Temperature Sensor

Trip Point Accuracy (Includes V

Comparator Offset, and Temperature

REF

, DAC,

-55°C ≤ TA ≤ +110°C

+120°C ±4 °C (max)

Sensitivity errors)

Trip Point Hysteresis HYST = GND 11 °C

HYST = V

V

V

Output Temperature Sensitivity

TEMP

Temperature Sensitivity Error to

TEMP

Equation:

VO = (−3.479×10−6×(T−30)2)

+ (−1.082×10−2×(T−30)) + 1.8015V

−30°C ≤ TA ≤ 120°C,

2.7V ≤ V+ ≤ 5.5V

−55°C ≤ TA ≤ 120°C,

4.5V ≤ V+ ≤ 5.5V

TA = 30°C ±2.5 °C (max)

V

Load Regulation

TEMP

Source ≤ 1 μA
Sink ≤ 40 μA

V

Line Regulation

TEMP

+2.7V ≤ V+ ≤ +5.5V,

−30°C ≤ TA ≤ +120°C

I

S

Supply Current 16 20

Digital Output and Input

I

OUT(“1”)

Logical “1” Output Leakage Current

V+ = +5.0V 0.001 1 µA (max)

(Note 9)

V

OUT(“0”)

V

OUT(“1”)

Logical “0” Output Voltage I

Logical “1” Push-Pull Output Voltage

= +1.2mA and

OUT

+

V

≥2.7V; I

+

and V

≥4.5V; (Note 8)

I

= 500µA, V+ ≥

SOURCE

2.7V

I

= 800µA, V

SOURCE

+

≥4.5V

V

IH

HYST Input Logical ”1“ Threshold

0.8 × V

Voltage

V

IL

HYST Input Logical ”0“ Threshold

0.2 × V

Voltage

load current = 0µA unless otherwise specified. Boldface

TEMP

(Note 6)

Limits

(Note 7)

±3 °C (max)

+

2

−10.82

°C

±3 °C (max)

±3 °C (max)

0.070 mV

0.7 mV (max)

−0.2 mV/V

40

0.4 V (max)

= +3.2mA

OUT

0.8 × V

+

V+ − 1.5 V (min)

+

+

(Limits)

mV/°C

µA (max)
µA (max)

V (min)

V (min)

V (max)

2500V

250V

MAX

+5.5V

3 www.national.com