LM60BIM3X National Semiconductor, LM60BIM3X Datasheet - Page 6

• Manufacturer Part Number: LM60BIM3X
• Description: IC TEMP SENSOR 2.7V SOT23-3
• Manufacturer: National Semiconductor

Specifications of LM60BIM3X

• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Other names: *LM60BIM3X

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1.0 Mounting
The LM60 can be applied easily in the same way as other
integrated-circuit temperature sensors. It can be glued or ce-
mented to a surface. The temperature that the LM60 is sens-
ing will be within about +0.1°C of the surface temperature 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 intermediate
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 mea-
sured. These printed circuit board lands and traces will not
cause the LM60's temperature to deviate from the desired
temperature.
Alternatively, the LM60 can be mounted inside a sealed-end
metal tube, and can then be dipped into a bath or screwed
*-Part soldered to 30 gauge wire.
**-Heat sink used is ½ square printed circuit board with 2 oz. foil with part attached as shown in
***-Part glued or leads soldered to 1” square of 1/16” printed circuit board with 2 oz. foil or similar.
Still air
Moving air
(°C/W)
θ
450
no heat sink
JA
SOT-23*
T
0.17
J
(°C)
− T
FIGURE 3. Temperature Rise of LM60 Due to
Self-Heating and Thermal Resistance (θ
A
FIGURE 2. Printed Circuit Board Used
for Heat Sink to Generate All Curves.
with 2 oz. Copper Foil or Similar.
½ Square Printed Circuit Board
(°C/W)
θ
260
180
small heat fin
JA
SOT-23**
T
J
0.07
(°C)
0.1
− T
6
A
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 connections.
The thermal resistance junction to ambient (θ
rameter used to calculate the rise of a device junction tem-
perature due to the device power dissipation. For the LM60
the equation used to calculate the rise in the die temperature
is as follows:
where I
the output.
The table shown in
perature of the LM60 without any loading, and the thermal
resistance for different conditions.
T
θ
180
J
90
= T
Q
JA
no heat fin
is the quiescent current and I
TO-92*
A
1268114
+ θ
T
JA
JA
0.034
0.07
J
)
[(+V
− T
Figure 3
A
S
I
Q
) + (+V
Figure 2
summarizes the rise in die tem-
θ
140
70
small heat fin
JA
S
TO-92***
− V
.
L
O
is the load current on
) I
T
0.026
L
0.05
J
]
− T
JA
A
) is the pa-