MMDF2N02E Motorola, MMDF2N02E Datasheet - Page 7

• Manufacturer Part Number: MMDF2N02E
• Description: DUAL TMOS MOSFET 3.6 AMPERES 25 VOLTS
• Manufacturer: Motorola

design. The footprint for the semiconductor packages must be
the correct size to insure proper solder connection interface
pad size. These can vary from the minimum pad size for
soldering to the pad size given for maximum power
dissipation. Power dissipation for a surface mount device is
determined by T J(max) , the maximum rated junction
temperature of the die, R JA , the thermal resistance from the
device junction to ambient; and the operating temperature, T A .
Using the values provided on the data sheet for the SO–8
package, P D can be calculated as follows:
ratings table on the data sheet. Substituting these values into
temperature of the device. When the entire device is heated
to a high temperature, failure to complete soldering within a
short time could result in device failure. Therefore, the
following items should always be observed in order to
minimize the thermal stress to which the devices are
subjected.
Motorola TMOS Power MOSFET Transistor Device Data
Surface mount board layout is a critical portion of the total
The power dissipation of the SO–8 is a function of the input
The values for the equation are found in the maximum
The melting temperature of solder is higher than the rated
Always preheat the device.
The delta temperature between the preheat and soldering
When preheating and soldering, the temperature of the
should be 100 C or less.*
leads and the case must not exceed the maximum
temperature ratings as shown on the data sheet. When
using infrared heating with the reflow soldering method,
the difference shall be a maximum of 10 C.
MINIMUM RECOMMENDED FOOTPRINT FOR SURFACE MOUNTED APPLICATIONS
INFORMATION FOR USING THE SO–8 SURFACE MOUNT PACKAGE
P D =
T J(max) – T A
R JA
0.024
0.6
0.275
7.0
SOLDERING PRECAUTIONS
SO–8 POWER DISSIPATION
between the board and the package. With the correct pad
geometry, the packages will self–align when subjected to a
solder reflow process.
the equation for an ambient temperature T A of 25 C, one can
calculate the power dissipation of the device which in this case
is 2.0 Watts.
recommended footprint on a glass epoxy printed circuit board
to achieve a power dissipation of 2.0 Watts using the footprint
shown. Another alternative would be to use a ceramic
substrate or an aluminum core board such as Thermal Clad .
Using board material such as Thermal Clad, the power
dissipation can be doubled using the same footprint.
* Soldering a device without preheating can cause excessive
thermal shock and stress which can result in damage to the
device.
The 62.5 C/W for the SO–8 package assumes the
The soldering temperature and time shall not exceed
When shifting from preheating to soldering, the maximum
After soldering has been completed, the device should be
Mechanical stress or shock should not be applied during
260 C for more than 10 seconds.
temperature gradient shall be 5 C or less.
allowed to cool naturally for at least three minutes.
Gradual cooling should be used as the use of forced
cooling will increase the temperature gradient and result
in latent failure due to mechanical stress.
cooling
0.060
0.155
1.52
4.0
0.050
1.270
inches
P D =
mm
150 C – 25 C
62.5 C/W
= 2.0 Watts
MMDF2N02E
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