NSC LM56CIMM, LM56CIM, LM56BIM Datasheet

LM56
Dual Output Low Power Thermostat

LM56 Dual Output Low Power Thermostat

April 2000

General Description

The LM56 is a precision low power thermostat. Two stable
temperature trip points (V
ing down the LM56 1.250V bandgap voltage reference using
3 external resistors. The LM56hastwodigitaloutputs.OUT1
goes LOW when the temperature exceeds T1 and goes
HIGH when the the temperature goes below (T1–T
Similarly, OUT2 goes LOW when the temperature exceeds
T2 and goes HIGH when the temperature goes below
(T2–T

The LM56 is available in an 8-lead Mini-SO8 surface mount
package and an 8-lead small outline package.

HYST

). T

is an internally set 5˚C typical hysteresis.

HYST

and VT2) are generated by divid-

T1

HYST

Applications

n Microprocessor Thermal Management
n Appliances
n Portable Battery Powered 3.0V or 5V Systems
n Fan Control
n Industrial Process Control
n HVAC Systems
n Remote Temperature Sensing
n Electronic System Protection

Features

n Digital outputs support TTL logic levels
n Internal temperature sensor
n 2 internal comparators with hysteresis
n Internal voltage reference
n Currently available in 8-pin SO plastic package

).

n Future availability in the 8-pin Mini-SO8 package

Key Specifications

n Power Supply Voltage 2.7V–10V
n Power Supply Current 230 µA (max)
n V

REF

n Hysteresis Temperature 5˚C
n Internal Temperature Sensor

Output Voltage (+6.20 mV/˚C x T) +395 mV

n Temperature Trip Point Accuracy:

+25˚C
+25˚C to +85˚C

−40˚C to +125˚C

Simplified Block Diagram and Connection Diagram

1.250V±1% (max)

LM56BIM LM56CIM

±

2˚C (max)

±

2˚C (max)

±

3˚C (max)

±

3˚C (max)

±

3˚C (max)

±

4˚C (max)

DS012893-2

DS012893-1

Order

Number

NS
Package
Number

Transport
Media

Package

Marking

© 2000 National Semiconductor Corporation DS012893 www.national.com

LM56BIM LM56BIMX LM56CIM LM56CIMX LM56BIMM LM56BIMMX LM56CIMM LM56CIMMX

M08A M08A M08A M08A MUA08A MUA08A MUA08A MUA08A

SOP-8 SOP-8 SOP-8 SOP-8 MSOP-8 MSOP-8 MSOP-8 MSOP-8

2500 Units 2500 Units 3500 Units 3500 Units

Rail Tape &

Reel

LM56BIM LM56BIM LM56CIM LM56CIM T02B T02B T02C T02C

Rail Tape &

Reel

Rail Tape & Reel Rail Tape & Reel

Typical Application

LM56

VT1= 1.250V x (R1)/(R1 + R2 + R3)

= 1.250V x (R1 + R2)/(R1 + R2 + R3)

V

T2

where:
(R1+R2+R3)=27kΩand

= [6.20 mV/˚C x T] + 395 mV therefore:

V

T1 or T2

/(1.25V) x 27 kΩ

R1=V

T1

R2=(V
R3=27kΩ−R1−R2

/(1.25V) x 27 kΩ)−R1

T2

DS012893-3

FIGURE 1. Microprocessor Thermal Management

www.national.com 2

LM56

Absolute Maximum Ratings (Note 1)

Input Voltage 12V
Input Current at any pin (Note 2) 5 mA
Package Input Current(Note 2) 20 mA
Package Dissipation at T

(Note 3) 900 mW

ESD Susceptibility (Note 4)

Human Body Model 1000V
Machine Model 200V

= 25˚C

A

Vapor Phase (60 seconds) 215˚C
Infrared (15 seconds) 220˚C

Storage Temperature −65˚C to + 150˚C

Operating Ratings(Note 1)

Operating Temperature Range T
LM56BIM, LM56CIM −40˚C ≤ TA≤ +125˚C

+

Positive Supply Voltage (V
Maximum V

OUT1

and V

) +2.7V to +10V

OUT2

MIN

≤ TA≤ T

Soldering Information

SO Package (Note 5) :

LM56 Electrical Characteristics

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

its apply for TA=TJ=T

MIN

to T

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

MAX

Symbol Parameter Conditions (Note 6) Limits Limits (Limits)

Temperature Sensor

Trip Point Accuracy (Includes
V

, Comparator Offset, and +25˚C ≤ TA≤ +85˚C

REF

Temperature Sensitivity errors) −40˚C ≤ T
Trip Point Hysteresis T

= −40˚C 4 3 3 ˚C (min)

A

T

= +25˚C 5 3.5 3.5 ˚C (min)

A

T

= +85˚C 6 4.5 4.5 ˚C (min)

A

T

= +125˚C 6 4 4 ˚C (min)

A

Internal Temperature +6.20 mV/˚C
Sensitivity
Temperature Sensitivity Error

Output Impedance −1 µA ≤ I
Line Regulation +3.0V ≤ V

+25˚C≤T
+3.0V ≤ V

−40˚C≤T
+2.7V ≤ V

V

and VT2Analog Inputs

T1

I

BIAS

V

V

V

V

∆V

IN

OS

REF

REF

Output

REF

Analog Input Bias Current 150 300 300 nA (max)
Analog Input Voltage Range V+−1 V

Comparator Offset 2 88mV (max)

V

Nominal 1.250V V

REF

V

Error

REF

/∆V+Line Regulation +3.0V ≤ V+≤ +10V 0.13 0.25 0.25 mV/V (max)

+2.7V ≤ V

∆V

/∆ILLoad Regulation Sourcing +30 µA ≤ IL≤ +50 µA 0.15 0.15 mV/µA

REF

load current = 50 µA unless otherwise specified. Boldface lim-

REF

Typical LM56BIM LM56CIM Units

(Note 7) (Note 7)

≤ +125˚C

A

±

2

±

2

±

3

±

3 ˚C (max)

±

3 ˚C (max)

±

4 ˚C (max)

6 6 ˚C (max)

6.5 6.5 ˚C (max)

7.5 7.5 ˚C (max)

8 8 ˚C (max)

±

2

±

3

≤ +40 µA 1500 1500 Ω (max)

L

+

≤ +10V,

≤+85˚C

A

+

≤ +10V,

<

A

+

≤ +3.3V

25˚C

±

±

±

0.36

0.61

2.3

±

3 ˚C (max)

±

4 ˚C (max)

±

0.36 mV/V (max)

±

0.61 mV/V (max)

±

2.3 mV (max)

GND V

±

1

±

12.5

+

≤ +3.3V 0.15 1.1 1.1 mV (max)

±

1 % (max)

±

12.5 mV (max)

(max)

MAX

+10V

www.national.com3

LM56 Electrical Characteristics

LM56

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

its apply for TA=TJ=T

MIN

to T

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

MAX

load current = 50 µA unless otherwise specified. Boldface lim-

REF

Symbol Parameter Conditions Typical Limits Units

(Note 6) (Note 7) (Limits)

+

V

Power Supply

I

S

Supply Current V+= +10V 230 µA (max)

+

V

= +2.7V 230 µA (max)

Digital Outputs

I

OUT(“1”)

Logical “1” Output Leakage V+= +5.0V 1 µA (max)
Current

V

OUT(“0”)

Note 1: Absolute MaximumRatings indicate limitsbeyond which damageto thedevice may occur. Operating Ratingsindicate conditionsfor which thedevice is func­tional, but do not guarantee specific performance limits. For guaranteed specifications andtest conditions, see the Electrical Characteristics. The guaranteedspeci­fications apply only for the test conditions listed. Some performance characteristics may degrade when the device is not operated under the listed test conditions.

Note 2: When the input voltage(V
mum package input current rating limits the number of pins that can safely exceed the power supplies with an input current of 5 mA to four.

Note 3: The maximum power dissipation must be derated at elevated temperaturesand is dictated by T
bient thermal resistance) andT
in the Absolute Maximum Ratings, whichever is lower. For this device, T
types when board mounted follow:

Logical “0” Output Voltage I

) at anypin exceeds the power supply (V

I

(ambient temperature). Themaximum allowable power dissipation at any temperatureis PD=(T

A

= +50 µA 0.4 V (max)

OUT

<

GND or V

I

= 125˚C. For this device the typical thermal resistance (θJA) of the different package

Jmax

>

V+), the currentat that pin should be limitedto 5 mA. The 20mA maxi-

I

Jmax

(maximum junction temperature), θJA(junction to am-

)/θJAor the number given

Jmax–TA

Package Type θ

JA

M08A 110˚C/W

MUA08A 250˚C/W

Note 4: The humanbody model isa 100 pFcapacitor discharge througha 1.5kΩ resistor intoeach pin. Themachine modelis a 200pF capacitor dischargeddirectly
into each pin.

Note 5: See AN450“Surface Mounting Methods andTheir Effects onProduct Reliability” or thesection titled “Surface Mount”found in anypost 1986 National Semi­conductor Linear Data Book for other methods of soldering surface mount devices.

Note 6: Typicals are at T
Note 7: Limits are guaranteed to National’s AOQL(Average Outgoing Quality Level).

= 25˚C and represent most likely parametric norm.

J=TA

www.national.com 4