LM60
2.7V, SOT-23 or TO-92 Temperature Sensor
General Description
The LM60 is a precision integrated-circuit temperature sen-
sor that can sense a -40C to +125C temperature range
while operating from a single +2.7V supply. The LM60's
output voltage is linearly proportional to Celsius (Centigrade)
temperature (+6.25 mV/C) and has a DC offset of +424 mV.
The offset allows reading negative temperatures without the
need for a negative supply. The nominal output voltage of the
LM60 ranges from +174 mV to +1205 mV for a -40C to
+125C temperature range. The LM60 is calibrated to pro-
vide accuracies of
2.0C at room temperature and
3C
over the full -25C to +125C temperature range.
The LM60's linear output, +424 mV offset, and factory cali-
bration simplify external circuitry required in a single supply
environment where reading negative temperatures is re-
quired. Because the LM60's quiescent current is less than
110 A, self-heating is limited to a very low 0.1C in still air in
the SOT-23 package. Shutdown capability for the LM60 is
intrinsic because its inherent low power consumption allows
it to be powered directly from the output of many logic gates.
Features
n
Calibrated linear scale factor of +6.25 mV/C
n
Rated for full -40 to +125C range
n
Suitable for remote applications
n
Available in SOT-23 and TO-92 packages
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
Key Specifications
n
Accuracy at 25C:
2.0 and
3.0C (max)
n
Accuracy for -40C to +125C:
4.0C (max)
n
Accuracy for -25C to +125C:
3.0C (max)
n
Temperature Slope:
+6.25mV/C
n
Power Supply Voltage Range:
+2.7V to +10V
n
Current Drain
@
25C:
110A (max)
n
Nonlinearity:
0.8C (max)
n
Output Impedance:
800
(max)
Typical Application
Connection Diagrams
SOT-23
01268101
Top View
See NS Package Number MA03B
TO-92
01268123
See NS Package Number Z03A
01268102
V
O
= (+6.25 mV/C x T C) + 424 mV
Temperature (T)
Typical V
O
+125C
+1205 mV
+100C
+1049 mV
+25C
+580 mV
0C
+424 mV
-25C
+268 mV
-40C
+174 mV
FIGURE 1. Full-Range Centigrade Temperature Sensor
(-40C to +125C) Operating from a Single Li-Ion
Battery Cell
July 2001
LM60
2.7V
,
SOT
-23
or
T
O-92
T
emperature
Sensor
2001 National Semiconductor Corporation
DS012681
www.national.com
Ordering Information
Order
Number
Device
Marking
Supplied In
Accuracy Over
Specified
Temperature
Range
Specified
Temperature
Range
Package Type
LM60BIM3
T6B
1000 Units on Tape and Reel
3
-25C
T
A
+125C
SOT-23
LM60BIM3X
T6B
3000 Units on Tape and Reel
LM60CIM3
T6C
1000 Units on Tape and Reel
4
-40C
T
A
+125C
LM60CIM3X
T6C
3000 Units on Tape and Reel
LM60BIZ
LM60BIZ Bulk
3
-25C
T
A
+125C
TO-92
LM60CIZ
LM60CIZ Bulk
4
-40C
T
A
+125C
LM60
www.national.com
2
Absolute Maximum Ratings
(Note 1)
Supply Voltage
+12V to -0.2V
Output Voltage
(+V
S
+ 0.6V) to
-0.6V
Output Current
10 mA
Input Current at any pin (Note 2)
5 mA
ESD Susceptibility (Note 3) :
Human Body Model
2500V
Machine Model
SOT-23
TO-92
250V
200V
Recommended Lead Temperature
(Note 4):
SOT Package:
Vapor Phase (60 sec)
Infrared (15 sec)
TO-92 Package (3 sec, dwell time)
+215C
+220C
+240C
Storage Temperature
-65C to
+150C
Maximum Junction Temperature
(T
JMAX
)
+125C
Operating Ratings
(Note 1)
Specified Temperature Range:
T
MIN
T
A
T
MAX
LM60B
-25C
T
A
+125C
LM60C
-40C
T
A
+125C
Supply Voltage Range (+V
S
)
+2.7V to +10V
Thermal Resistance,
JA
(Note
5)
SOT-23
TO-92
450C/W
180C/W
Electrical Characteristics
Unless otherwise noted, these specifications apply for +V
S
= +3.0 V
DC
and I
LOAD
= 1 A. Boldface limits apply for T
A
= T
J
= T
MIN
to T
MAX
; all other limits T
A
= T
J
= 25C.
Parameter
Conditions
Typical
(Note 6)
LM60B
LM60C
Units
(Limit)
Limits
Limits
(Note 7)
(Note 7)
Accuracy (Note 8)
2.0
3.0
C (max)
3.0
4.0
C (max)
Output Voltage at 0C
+424
mV
Nonlinearity (Note 9)
0.6
0.8
C (max)
Sensor Gain
+6.25
+6.06
+6.00
mV/C (min)
(Average Slope)
+6.44
+6.50
mV/C (max)
Output Impedance
800
800
(max)
Line Regulation (Note 10)
+3.0V
+V
S
+10V
0.3
0.3
mV/V (max)
+2.7V
+V
S
+3.3V
2.3
2.3
mV (max)
Quiescent Current
+2.7V
+V
S
+10V
82
110
110
A (max)
125
125
A (max)
Change of Quiescent Current
+2.7V
+V
S
+10V
5.0
A (max)
Temperature Coefficient of
0.2
A/C
Quiescent Current
Long Term Stability (Note 11)
T
J
=T
MAX
=+125C, for
0.2
C
1000 hours
Note 1: Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. Operating Ratings indicate conditions for which the device is
functional, but do not guarantee specific performance limits. For guaranteed specifications and test conditions, see the Electrical Characteristics. The guaranteed
specifications 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
I
) at any pin exceeds power supplies (V
I
<
GND or V
I
>
+V
S
), the current at that pin should be limited to 5 mA.
Note 3: The human body model is a 100 pF capacitor discharged through a 1.5 k
resistor into each pin. The machine model is a 200 pF capacitor discharged
directly into each pin.
Note 4: See the URL "http://www.national.com/packaging/" for other recomdations and methods of soldering surface mount devices.
Note 5: The junction to ambient thermal resistance (
JA
) is specified without a heat sink in still air.
Note 6: Typicals are at T
J
= T
A
= 25C and represent most likely parametric norm.
Note 7: Limits are guaranteed to National's AOQL (Average Outgoing Quality Level).
Note 8: Accuracy is defined as the error between the output voltage and +6.25 mV/C times the device's case temperature plus 424 mV, at specified conditions of
voltage, current, and temperature (expressed in C).
Note 9: Nonlinearity is defined as the deviation of the output-voltage-versus-temperature curve from the best-fit straight line, over the device's rated temperature
range.
LM60
www.national.com
3
Electrical Characteristics
(Continued)
Note 10: Regulation is measured at constant junction temperature, using pulse testing with a low duty cycle. Changes in output due to heating effects can be
computed by multiplying the internal dissipation by the thermal resistance.
Note 11: For best long-term stability, any precision circuit will give best results if the unit is aged at a warm temperature, and/or temperature cycled for at least 46
hours before long-term life test begins. This is especially true when a small (Surface-Mount) part is wave-soldered; allow time for stress relaxation to occur. The
majority of the drift will occur in the first 1000 hours at elevated temperatures. The drift after 1000 hours will not continue at the first 1000 hour rate.
Typical Performance Characteristics
To generate these curves the LM60 was mounted to a
printed circuit board as shown in
Figure 2.
Thermal Resistance
Junction to Air
Thermal Time Constant
Thermal Response in
Still Air with Heat Sink
01268103
01268104
01268105
Thermal Response
in Stirred Oil Bath
with Heat Sink
Start-Up Voltage
vs. Temperature
Thermal Response in Still
Air without a Heat Sink
01268106
01268107
01268108
Quiescent Current
vs. Temperature
Accuracy vs Temperature
Noise Voltage
01268109
01268110
01268111
LM60
www.national.com
4
Typical Performance Characteristics
To generate these curves the LM60 was mounted to a
printed circuit board as shown in
Figure 2. (Continued)
Supply Voltage
vs Supply Current
Start-Up Response
01268112
01268122
1.0 Mounting
The LM60 can be applied easily in the same way as other
integrated-circuit temperature sensors. It can be glued or
cemented to a surface. The temperature that the LM60 is
sensing will be within about +0.1C of the surface tempera-
ture that LM60's leads are attached to.
This presumes that the ambient air temperature is almost the
same as the surface temperature; if the air temperature were
much higher or lower than the surface temperature, the
actual temperature of the LM60 die would be at an interme-
diate temperature between the surface temperature and the
air temperature.
To ensure good thermal conductivity the backside of the
LM60 die is directly attached to the GND pin. The lands and
traces to the LM60 will, of course, be part of the printed
circuit board, which is the object whose temperature is being
measured. These printed circuit board lands and traces will
not cause the LM60's temperature to deviate from the de-
sired temperature.
Alternatively, the LM60 can be mounted inside a sealed-end
metal tube, and can then be dipped into a bath or screwed
into a threaded hole in a tank. As with any IC, the LM60 and
accompanying wiring and circuits must be kept insulated and
dry, to avoid leakage and corrosion. This is especially true if
the circuit may operate at cold temperatures where conden-
sation can occur. Printed-circuit coatings and varnishes such
as Humiseal and epoxy paints or dips are often used to
ensure that moisture cannot corrode the LM60 or its connec-
tions.
The thermal resistance junction to ambient (
JA
) is the
parameter used to calculate the rise of a device junction
temperature due to the device power dissipation. For the
LM60 the equation used to calculate the rise in the die
temperature is as follows:
T
J
= T
A
+
JA
[(+V
S
I
Q
) + (+V
S
- V
O
) I
L
]
where I
Q
is the quiescent current and I
L
is the load current on
the output.
The table shown in
Figure 3 summarizes the rise in die
temperature of the LM60 without any loading, and the ther-
mal resistance for different conditions.
01268114
FIGURE 2. Printed Circuit Board Used
for Heat Sink to Generate All Curves.
1
/
2
" Square Printed Circuit Board
with 2 oz. Copper Foil or Similar.
LM60
www.national.com
5
PDF 
ZIP