SiP32448, SiP32449

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Vishay Siliconix

S15-1920-Rev. C, 24-Aug-15

5

Document Number: 62959

THIS DOCUMENT IS SUBJECT TO CHANGE WITHOUT NOTICE. THE PRODUCTS DESCRIBED HEREIN AND THIS DOCUMENT

In order to calculate the maximum allowed DC current the

switch

temperature

dependency

should

be

considered.

As an example let us calculate maximum load current

the following formula:

percent change per degree C.

is the maximum allowed junction temperature (125 °C).

Therefore,

The maximum current limit is then determined by



Which in this case is 2.38 A.



Due to device limitation the max switch DC current

should exceed 3 A in any condition.

To obtain the highest power dissipation the power pad of

the device should be connected to a heat sink on the printed

circuit board. Figure 4 shows a typical PCB layout. All

sized adequately to carry the maximum continuous current.

Negative Input Voltage

The SiP32448 and SiP32449 can withstand maximum

negative 2 V at its input due to any spike from abnormal or

fault condition of the system.

Recommended Board Layout

For improved performance, all traces should be as short as

possible to minimize stray inductances and parasitic effects.

The input and output capacitors should be kept as close

as possible to the input and output pins respectively.

Connecting the central exposed pad to GND, using wide

traces for input, output, and GND help reducing the case to

ambient thermal impedance. See fig. 4.

BOARD LAYOUT

Fig. 4 - Recommended Board Layout

TYPICAL APPLICATION SCHEMATIC

Fig. 5 - Application Schematic

43 m

Ω x (1 + 0.31 x (125 - 25)/100 ) ≈ 57 mΩ

)

(

(max.)

(max.)

on

DS

LOAD

R

P

I

<