Rainbow Electronics LM20 User Manual

LM20

2.4V, 10µA, SC70, micro SMD Temperature Sensor

General Description

The LM20 is a precision analog output CMOS integrated­circuit temperature sensor that operates over a −55˚C to
+130˚C temperature range. The power supply operating
range is +2.4 V to +5.5 V. The transfer function of LM20 is
predominately linear, yet has a slight predictable parabolic
curvature. The accuracy of the LM20 when specified to a
parabolic transfer function is
ture of +30˚C. The temperature error increases linearly and
reaches a maximum of
extremes. The temperature range is affected by the power
supply voltage. At a power supply voltage of 2.7 V to 5.5 V
the temperature range extremes are +130˚C and −55˚C.
Decreasing the power supply voltage to 2.4 V changes the
negative extreme to −30˚C, while the positive remains at
+130˚C.

The LM20’s quiescent current is less than 10 µA. Therefore,
self-heating is less than 0.02˚C in still air. Shutdown capa­bility for the LM20 is intrinsic because its inherent low power
consumption allows it to be powered directly from the output
of many logic gates or does not necessitate shutdown at all.

±

1.5˚C at an ambient tempera-

±

2.5˚C at the temperature range

Applications

n Cellular Phones
n Computers
n Power Supply Modules

n Battery Management
n FAX Machines
n Printers
n HVAC
n Disk Drives
n Appliances

Features

n Rated for full −55˚C to +130˚C range
n Available in an SC70 and a micro SMD package
n Predictable curvature error
n Suitable for remote applications

Key Specifications

j

Accuracy at +30˚C

j

Accuracy at +130˚C & −55˚C

j

Power Supply Voltage Range +2.4V to +5.5V

j

Current Drain 10 µA (max)

j

Nonlinearity

j

Output Impedance 160 Ω (max)

j

Load Regulation

<

<

I

0µA

+16 µA −2.5 mV (max)

L

±

1.5 to±4 ˚C (max)

±

2.5 to±5 ˚C (max)

March 2004

±

0.4 % (typ)

LM20 2.4V, 10µA, SC70, micro SMD Temperature Sensor

Typical Application

Full-Range Celsius (Centigrade) Temperature Sensor (−55˚C to +130˚C)
Operating from a Single Li-Ion Battery Cell

VO= (−3.88x10−6xT2) + (−1.15x10−2xT) + 1.8639

where:

T is temperature, and V

is the measured output voltage of the LM20.

O

10090802

Output Voltage vs Temperature

10090824

© 2004 National Semiconductor Corporation DS100908 www.national.com

Typical Application (Continued)

LM20

Connection Diagrams

SC70-5 micro SMD

Temperature (T) Typical V

+130˚C +303 mV

+100˚C +675 mV

+80˚C +919 mV

+30˚C +1515 mV

+25˚C +1574 mV

0˚C +1863.9 mV

−30˚C +2205 mV

−40˚C +2318 mV

−55˚C +2485 mV

O

Note:

- GND (pin 2) may be grounded or left floating. For optimum thermal

conductivity to the pc board ground plane pin 2 should be grounded.

- NC (pin 1) should be left floating or grounded. Other signal traces

should not be connected to this pin.

Top View

See NS Package Number MAA05A

10090801

Note:

- Pin numbers are referenced to the package marking text orientation.

- Reference JEDEC Registration MO-211, variation BA

- The actual physical placement of package marking will vary slightly from
part to part. The package marking will designate the date code and will vary
considerably. Package marking does not correlate to device type in any way.

Top View

See NS Package Number BPA04DDC and TLA04ZZA

Ordering Information

Order Temperature Temperature NS Package Device

Number Accuracy Range Number Marking Transport Media

LM20BIM7

LM20BIM7X

LM20CIM7

LM20CIM7X

LM20SIBP

LM20SIBPX

LM20SITL

LM20SITLX

±

2.5˚C −55˚C to +130˚C MAA05A T2B 1000 Units on Tape and Reel

±

2.5˚C −55˚C to +130˚C MAA05A T2B 3000 Units on Tape and Reel

±

5˚C −55˚C to +130˚C MAA05A T2C 1000 Units on Tape and Reel

±

5˚C −55˚C to +130˚C MAA05A T2C 3000 Units on Tape and Reel

±

3.5˚C −40˚C to +125˚C BPA04DDC Date

250 Units on Tape and Reel

Code

±

3.5˚C −40˚C to +125˚C BPA04DDC Date

3000 Units on Tape and Reel

Code

±

3.5˚C −40˚C to +125˚C TLA04ZZA Date

250 Units on Tape and Reel

Code

±

3.5˚C −40˚C to +125˚C TLA04ZZA Date

3000 Units on Tape and Reel

Code

10090832

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LM20

Absolute Maximum Ratings (Note 1)

Supply Voltage +6.5V to −0.2V

Output Voltage (V

Output Current 10 mA

Input Current at any pin (Note 2) 5 mA

Storage Temperature −65˚C to

Maximum Junction Temperature
(T

) +150˚C

JMAX

ESD Susceptibility (Note 3) :

Human Body Model 2500 V

Machine Model 250 V

Soldering process must comply with National’s

+

+ 0.6 V) to

−0.6 V

+150˚C

Operating Ratings(Note 1)

Specified Temperature Range: T

LM20B, LM20C with

+

2.4 V ≤ V

≤ 2.7 V −30˚C ≤ TA≤ +130˚C

LM20B, LM20C with

+

2.7 V ≤ V

≤ 5.5 V −55˚C ≤ TA≤ +130˚C

LM20S with

+

2.4 V ≤ V

≤ 5.5 V −30˚C ≤ TA≤ +125˚C

LM20S with

2.7 V ≤ V+≤ 5.5 V −40˚C ≤ TA≤ +125˚C

Supply Voltage Range (V

Thermal Resistance, θ

+

) +2.4 V to +5.5 V

(Note 5)

JA

SC-70
micro SMD

MIN

≤ TA≤ T

MAX

415˚C/W
340˚C/W

Reflow Temperature Profile specifications. Refer to
www.national.com/packaging. (Note 4)

Electrical Characteristics

Unless otherwise noted, these specifications apply for V+= +2.7 VDC. Boldface limits apply for TA=TJ=T
other limits T

Parameter Conditions Typical

= 25˚C; Unless otherwise noted.

A=TJ

(Note 6)

LM20B LM20C LM20S Units

Limits Limits Limits

(Note 7) (Note 7) (Note 7)

Temperature to Voltage Error

= (−3.88x10−6xT2)

V

O

+ (−1.15x10

−2

xT) + 1.8639V

(Note 8)

= +25˚C to +30˚C

T

A

T

= +130˚C

A

T

= +125˚C

A

T

= +100˚C

A

T

= +85˚C

A

T

= +80˚C

A

T

= 0˚C

A

T

= −30˚C

A

T

= −40˚C

A

T

= −55˚C

A

±

1.5

±

2.5

±

2.5

±

2.2

±

2.1

±

2.0

±

1.9

±

2.2

±

2.3

±

2.5

±

4.0

±

5.0 ˚C (max)

±

5.0

±

4.7

±

4.6

±

4.5

±

4.4

±

4.7

±

4.8

±

5.0 ˚C (max)

±

2.5 ˚C (max)

±

3.5 ˚C (max)

±

3.2 ˚C (max)

±

3.1 ˚C (max)

±

3.0 ˚C (max)

±

2.9 ˚C (max)

±

3.3 ˚C (min)

±

3.5 ˚C (max)

Output Voltage at 0˚C +1.8639 V

Variance from Curve

Non-Linearity (Note 9) −20˚C ≤ T

Sensor Gain (Temperature

−30˚C ≤ T

Sensitivity or Average Slope)

≤ +80˚C

A

≤ +100˚C −11.77 −11.4

A

±

1.0 ˚C

±

0.4 %

−12.2

−11.0

−12.6

−11.0

−12.6

to equation:

=−11.77 mV/˚CxT+1.860V

V

O

Output Impedance 0 µA ≤ I

≤ +16 µA

L

160 160 160 Ω (max)

(Notes 11, 12)

Load Regulation(Note 10) 0 µA ≤ IL≤ +16 µA

−2.5 −2.5 −2.5 mV (max)

(Notes 11, 12)

+

Line Regulation +2. 4 V ≤ V

+5.0 V ≤ V

Quiescent Current +2. 4V ≤ V

+5.0V ≤ V

+2. 4V ≤ V

Change of Quiescent Current +2. 4 V ≤ V

≤ +5.0V +3.3 +3.7 +3.7 mV/V (max)

+

≤ +5.5 V +11 +11 +11 mV (max)

+

≤ +5.0V 4.5 7 7 7 µA (max)

+

≤ +5.5V 4.5 9 9 9 µA (max)

+

≤ +5.0V 4.5 10 10 10 µA (max)

+

≤ +5.5V +0.7 µA

Temperature Coefficient of −11 nA/˚C

Quiescent Current

Shutdown Current V

+

≤ +0.8 V 0.02 µA

to T

MIN

mV/˚C (min)

mV/˚C (max)

MAX

(Limit)

; all

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