sip32413 Vishay, sip32413 Datasheet - Page 10

• Manufacturer Part Number: sip32413
• Description: Dual 2 A, 1.2 V, Slew Rate Controlled Load Switch
• Manufacturer: Vishay

SiP32413, SiP32414
Vishay Siliconix
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
properly, it can be as low as V
APPLICATION INFORMATION
Input Capacitor
While bypass capacitors on the inputs are not required,
2.2 µF or larger capacitors for C
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
A 0.1 µF capacitor or larger across V
recommended to insure proper slew operation. C
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
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
reliability data, see www.vishay.com/ppg?71437.
www.vishay.com
10
IN(min)
IN
is recommended in almost
.
OUT
and GND is
OUT
may be
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
T
for the TDFN4 1.2 mm x 1.6 mm package, θ
and the ambient temperature, T
expressed as:
P
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
things: the package power dissipation and the R
ambient temperature.
As an example let us calculate the worst case maximum load
current at T
occurs at an input voltage of 1.2 V and is equal to 75 mΩ. The
R
the following formula:
R
Where T
we have
R
= 86.5 mΩ
The maximum current limit is then determined by
I
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.
LOAD
J(max.)
DS(ON
DS(ON)
DS(ON)
(max.)
(max.)
) at 70 °C can be extrapolated from this data using
= 125 °C, the junction-to-ambient thermal resistance
(at 70 °C) = R
(at 70 °C) = 75 mΩ x (1 + 0.0034 x (70 °C - 25 °C))
C
=
is 3400 ppm/°C. Continuing with the calculation
<
T
A
on
J
= 70 °C. The worst case R
(max.)
R
θ
P
J
the
DS
(max.)
-
A
(
ON
-
DS(ON)
T
maximum
)
A
=
(at 25 °C) x (1 + T
A
125
, which may be formulaically
S11-0366-Rev. A, 07-Mar-11
84
Document Number: 71437
-
junction
T
A
DS(ON)
J-A
temperature,
DS(ON)
C
= 84 °C/W,
x ΔT)
at 25 °C
at the