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Document Number: 71437

S11-0366-Rev. A, 07-Mar-11

Vishay Siliconix

SiP32413, SiP32414

DETAILED DESCRIPTION

SiP32413

and

SiP32414

are

dual

n-channel

power

MOSFETs designed as high side load switch with slew rate

control to prevent in-rush current. Once enable the device

charge pumps the gate of the power MOSFET to 5 V gate to

source voltage while controlling the slew rate of the turn on

time. The mostly constant gate to source voltage keeps the

on resistance low through out the input voltage range. For

SiP32414, when disable the output discharge circuit turns on

to help pull the output voltage to ground more quickly. For

both parts, in disable mode, the reverse blocking circuit is

activated to prevent current from going back to the input in

case the output voltage is higher than the input voltage. Input

voltage is needed for the reverse blocking circuit to work

APPLICATION INFORMATION

Input Capacitor

While bypass capacitors on the inputs are not required,

all applications. The bypass capacitors should be placed as

physically close as possible to the device’s input to be

effective in minimizing transients on the input. Ceramic

capacitors are recommended over tantalum because of their

ability to withstand input current surges from low impedance

sources such as batteries in portable devices.

Output Capacitor

increased without limit to accommodate any load transient

condition with only minimal affect on the turn on slew rate

time. There are no ESR or capacitor type requirement.

Control

The CNTRL pins are compatible with both TTL and CMOS

logic voltage levels.

Protection Against Reverse Voltage Condition

Both SiP32413 and SiP32414 contain reverse blocking

circuitries to protect the current from going to the input from

the output in case where the output voltage is higher than the

input voltage when the main switch is off. Supply voltages as

low as the minimum required input voltage are necessary for

these circuitries to work properly.

Thermal Considerations

SiP32413 and SiP32414 are designed to maintain constant

output load current. Due to physical limitations of the layout

and assembly of the device the maximum switch current is

2.4 A, as stated in the Absolute Maximum Ratings table.

However, another limiting characteristic for the safe

operating load current is the thermal power dissipation of the

package. To obtain the highest power dissipation (and a

thermal resistance of 84) the power pad of the device should

be connected to a heat sink on the printed circuit board.

The maximum power dissipation in any application is

dependant

on

the

maximum

junction

temperature,

for the TDFN4 1.2 mm x 1.6 mm package,

expressed as:

It then follows that, assuming an ambient temperature of

70 °C, the maximum power dissipation will be limited to about

655 mW.

So long as the load current is below the 2.0 A limit, the

maximum continuous switch current becomes a function two

ambient temperature.

As an example let us calculate the worst case maximum load

occurs at an input voltage of 1.2 V and is equal to 75 m

Ω. The

the following formula:

we have

= 86.5 m

Ω

The maximum current limit is then determined by

which in case is 2.75 A, assuming one switch turn on at a

time. Under the stated input voltage condition, if the 2.75 A

current limit is exceeded the internal die temperature will rise

and eventually, possibly damage the device.

Vishay Siliconix maintains worldwide manufacturing capability. Products may be manufactured at one of several qualified locations. Reliability data for Silicon

Technology and Package Reliability represent a composite of all qualified locations. For related documents such as package/tape drawings, part marking, and

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