FDC6324 Fairchild Semiconductor, FDC6324 Datasheet - Page 6

• Manufacturer Part Number: FDC6324
• Description: Integrated Load Switch
• Manufacturer: Fairchild Semiconductor

I N
FDC6324L Load Switch Application
Component Values
R1
R2
C1
Design Notes
R1 is needed to turn off Q2.
R2 can be used to soft start the switch in the case the output capacitance Co is small.
R2
By using R1 and R2 a certain amount of current is lost from the input. This bias current loss is given by
the equation
I
R2 and C
additional capacitance C1 can be added externally to slow down the turn on.
O N / O FF
BIAS_LOSS
should be at least 10 times smaller than R1 to guarantee Q1 turns on.
R1
RSS
APPLICATION CIRCUIT
Typical 10k - 1M
Typical 0 - 10k
Typical 1000pF
R 1
of Q2 make ramp for slow turn on. If excessive overshoot current occurs due to fast turn on,
Vin
Q2
R2
R2
Q1
when the switch is ON. I
C1
Co
(optional)
(optional)
LOAD
O U T
BIAS_LOSS
General Description
This device is particularly suited for computer
peripheral switching applications where 20V
input and 1A output current capability are
needed. This load switch integrates a small
N-Channel Power MOSFET (Q1) which drives a
large P-Channel Power MOSFET (Q2) in one
tiny SuperSOT
A load switch is usually configured for high side
switching so that the load can be isolated from
the active power source. A P-Channel Power
MOSFET, because it does not require its drive
voltage above the input voltage, is usually more
cost effective than using an N-Channel device in
this particular application. A large P-Channel
Power MOSFET minimizes voltage drop. By
using a small N-Channel device the driving
stage is simplified.
can be minimized by large R1.
TM
-6 package.
FDC6324L Rev. D