MMBT2369AT3 Ver la hoja de datos (PDF) - ON Semiconductor

Número de pieza

componentes Descripción

Fabricante

MMBT2369AT3

Switching Transistors NPN Silicon

ON Semiconductor 

MMBT2369LT1, MMBT2369ALT1

INFORMATION FOR USING THE SOT–23 SURFACE MOUNT PACKAGE

MINIMUM RECOMMENDED FOOTPRINT FOR SURFACE MOUNTED APPLICATIONS

Surface mount board layout is a critical portion of the total

design. The footprint for the semiconductor packages must

be the correct size to insure proper solder connection

0.037

0.95

interface between the board and the package. With the

correct pad geometry, the packages will self align when

subjected to a solder reflow process.

0.037

0.95

0.035

0.9

0.079

2.0

0.031

0.8

inches

mm

SOT–23

SOT–23 POWER DISSIPATION

The power dissipation of the SOT–23 is a function of the

SOLDERING PRECAUTIONS

pad size. This can vary from the minimum pad size for

The melting temperature of solder is higher than the rated

soldering to a pad size given for maximum power temperature of the device. When the entire device is heated

dissipation. Power dissipation for a surface mount device is to a high temperature, failure to complete soldering within

determined by TJ(max), the maximum rated junction

temperature of the die, RθJA, the thermal resistance from the

device junction to ambient, and the operating temperature,

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

TA. Using the values provided on the data sheet for the subjected.

SOT–23 package, PD can be calculated as follows:

• Always preheat the device.

PD =

TJ(max) – TA

RθJA

The values for the equation are found in the maximum

ratings table on the data sheet. Substituting these values into

the equation for an ambient temperature TA of 25°C, one can

calculate the power dissipation of the device which in this

case is 225 milliwatts.

• The delta temperature between the preheat and soldering

should be 100°C or less.*

• When preheating and soldering, the temperature of the

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.

• The soldering temperature and time shall not exceed

PD =

150°C – 25°C

556°C/W

= 225 milliwatts

260°C for more than 10 seconds.

• When shifting from preheating to soldering, the maximum

The 556°C/W for the SOT–23 package assumes the use of temperature gradient shall be 5°C or less.

the recommended footprint on a glass epoxy printed circuit • After soldering has been completed, the device should be

board to achieve a power dissipation of 225 milliwatts. allowed to cool naturally for at least three minutes.

There are other alternatives to achieving higher power Gradual cooling should be used as the use of forced

dissipation from the SOT–23 package. Another alternative cooling will increase the temperature gradient and result

would be to use a ceramic substrate or an aluminum core

board such as Thermal Clad®. Using a board material such

as Thermal Clad, an aluminum core board, the power

dissipation can be doubled using the same footprint.

in latent failure due to mechanical stress.

• Mechanical stress or shock should not be applied during

cooling.

* Soldering a device without preheating can cause

excessive thermal shock and stress which can result in

damage to the device.

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