FDC6324L
Integrated Load Switch
General Description Features
These Integrated Load Switches are produced using Fairchild's
proprietary, high cell density, DMOS technology. This very high
density process is especially tailored to minimize on-state
resistance and provide superior switching performance. These
devices are particularly suited for low voltage high side load
switch application where low conduction loss and ease of driving
are needed.
V
DROP
V
DROP
High density cell design for extremely low on-resistance.
V
ON/OFF
Body Model.
SuperSOTTM-6 package design using copper lead frame for superior
thermal and electrical capabilities.
March 1999
=0.2V @ VIN=12V, IL=1A, V
=0.3V @ VIN=5V, IL=1A, V
Zener protection for ESD ruggedness. >6KV Human
=1.5 to 8V
ON/OFF
=1.5 to 8V.
ON/OFF
SOT-23
SuperSOT -6
pin
1
TM
SuperSOTTM-6
Absolute Operating Range T
SuperSOTTM-8
4
Vin,R1
5
ON/OFF
6
R1,C1
= 25°C unless otherwise noted
A
SO-8
Q2
Q1
See Application Circuit
3
2
1
Vout,C1
Vout,C1
R2
SOT-223
EQUIVALENT CIRCUIT
IN
ON/OFF
SOIC-16
V
DROP
+
-
Symbol Parameter FDC6324L Units
V
IN
V
ON/OFF
I
L
P
D
TJ,T
ESD Electrostatic Discharge Rating MIL-STD-883D Human Body
Input Voltage Range 3 - 20 V
ON/OFF Voltage Range 1.5 - 8 V
Load Current @ V
=0.5V - Continuous (Note 1)
DROP
1.5 A
- Pulsed (Note 1 & 3) 2.5
Maximum Power Dissipation (Note 2a) 0.7 W
Operating and Storage Temperature Range -55 to 150 °C
STG
6 kV
Model (100pf/1500Ohm)
THERMAL CHARACTERISTICS
R
θJA
R
θJC
Thermal Resistance, Junction-to-Ambient (Note 2a) 180 °C/W
Thermal Resistance, Junction-to-Case (Note 2) 60 °C/W
OUT
© 1999 Fairchild Semiconductor Corporation
FDC6324L Rev. D
Electrical Characteristics (T
= 25°C unless otherwise noted)
A
Symbol Parameter Conditions Min Typ Max Units
OFF CHARACTERISTICS
I
FL
I
RL
Forward Leakage Current
Reverse Leakage Current
VIN = 20 V, V
VIN = -20 V, V
ON/OFF
ON/OFF
= 0 V
= 0 V
1 µA
-1 µA
ON CHARACTERISTICS (Note 3)
V
IN
V
ON/OFF
V
DROP
I
L
Notes:
1. VIN=20V, V
2. R
guaranteed by design while R
P
D
Typical R
Input Voltage 3 20 V
On/Off Voltage 1.5 8 V
Conduction Voltage Drop @ 1A
Load Current
=8V, V
ON/OFF
is the sum of the junction-to-case and case-to-ambient thermal resistance where the case thermal reference is defined as the solder mounting surface of the drain pins. R
θJA
TJ−T
(t) =
R
θJ A
θJA
a. 180oC/W when mounted on a 2oz minimum copper pad.
=0.5V, TA=25oC
DROP
is determined by the user's board design.
θCA
TJ−T
A
=
(t)
R
θJ C+RθCA
for single device operation using the board layouts shown below on FR-4 PCB in a still air environment:
2
A
= I
(t)× R
DS(ON)@T
D
(t)
VIN = 10 V, V
VIN = 5 V, V
V
= 0.2 V, VIN = 10 V, V
DROP
V
= 0.3 V, VIN = 5 V, V
DROP
J
ON/OFF
ON/OFF
= 3.3V
= 3.3 V
ON/OFF
ON/OFF
= 3.3 V
= 3.3 V
0.135 0.2 V
0.215 0.3
1 A
1
is
θJC
2a
Scale 1 : 1 on letter size paper
3. Pulse Test: Pulse Width < 300µs, Duty Cycle < 2.0%
FDC6324L Rev. D
Typical Electrical Characteristics (T
= 25 OC unless otherwise noted )
A
0.5
T = 125°C
J
0.4
T = 25°C
0.3
DROP
0.2
V , (V)
0.1
0
0 1 2 3 4
Figure 1. V
1
0.8
0.6
0.4
DROP
V (V)
0.2
0
1 2 3 4 5
DROP
I ,(A)
L
Versus IL at V
T = 125°C
J
T = 25°C
J
V (V)
IN
J
V = 12V
IN
V = 1.5 - 8V
ON/OFF
PW =300us, D≤ 2%
=12V. Figure 2. V
IN
I = 1A
L
V = 1.5 - 8V
ON/OFF
PW =300us, D≤ 2%
0.5
T = 125°C
0.4
J
T = 25°C
J
0.3
DROP
0.2
V , (V)
V = 5V
IN
V = 1.5 - 8V
0.1
0
0 1 2 3 4
DROP
0.45
0.4
0.35
0.3
RDS(ON), (Ohm)
0.25
0.2
0.15
0 1 2 3 4 5
I (A)
L
Versus IL at VIN=5.0V.
T = 125°C
J
T = 25°C
J
I , (A)
L
ON/OFF
PW =300us, D≤ 2%
I = 1A
L
V = 5V
IN
PW =300us, D≤ 2%
Figure 3. V
1
0.8
0.6
0.4
R ,(Ohm)(ON)
0.2
0
1 2 3 4 5
Versus V
DROP
T = 25°C
J
T = 125°C
J
V , (V)
IN
at IL=1A.
IN
I = 1A
L
V = 1.5 - 8V
ON/OFF
PW =300us, D≤ 2%
Figure 5. On Resistance Variation with
Input Voltage.
Figure 4. R
Versus IL at V
(ON)
=5.0V.
IN
FDC6324L Rev.D
Typical Electrical Characteristics (T
= 25 OC unless otherwise noted )
A
500
400
Vin = 12V
IL = 1A
Von/off = 5V
300
R1 = 300KOhm
Ci = 10uF
Co = 1uF
Time (us)
200
100
0
0 20 40 60 80 100
R2 (KOhm)
td(off)
tf
Figure 6. Switching Variation with R2 at
Vin=12V and R1=300KOhm.
500
Vin = 3.3V
IL = 1A
Von/off = 5V
400
R1 = 300KOhm
Ci = 10uF
Co = 1uF
300
Time (us)
200
100
0
0 20 40 60 80 100
R2 (KOhm)
tr
td(on)
tf
tr
td(on)
td(off)
500
400
300
Time (us)
200
td(off)
Vin = 5V
IL = 1A
Von/off = 5V
R1 = 300KOhm
Ci = 10uF
Co = 1uF
tf
100
tr
0
0 20 40 60 80 100
R2 (KOhm)
Figure 7. Switching Variation with R2 at
Vin=5V and R1=300KOhm.
120
100
80
60
40
% of Current Overshoot
20
Vin = 12V
5V
3.3V
0
0 20 40 60 80 100
R2 (KOhm)
IL = 1A
Von/off = 5V
R1 = 300KOhm
Ci = 10uF
Co = 1uF
td(on)
Figure 8. Switching Variation with R2 at
Vin=3.3V and R1=300KOhm.
2,000
IL = 1A
Von/off = 5V
R1 = 300KOhm
1,600
Ci = 10uF
Co = 1uF Vin = 3.3V
1,200
800
Vdrop (mV)
400
0
0 20 40 60 80 100
R2 (KOhm)
Figure 10. Vdrop Variation with Vin and R2 .
Figure 9. % of Current Overshoot Variation
with Vin and R2 .
t t
on off
t
V
d(on)
OUT
t
90%
10%
5V
12V
V
IN
10%
50%
PULSE WIDTH
t
d(off)
50%
90%
90%
10%
t
fr
INVERTED
Figure 11. Switching Waveforms.
FDC6324L Rev. D
Typical Electrical Characteristics (T
= 25 OC unless otherwise noted )
A
10
3
R(ON) LIMIT
1
0.3
1s
10ms
100ms
100us
1ms
DC
0.1
L
I , DRAIN CURRENT (A)
0.03
0.01
V = 12V
IN
SINGLE PULSE
JA
R = See Note 2a
θ
T = 25°C
A
0.1 0.2 0.5 1 2 5 10 20 30
V (V)
DROP
Figure 12. Safe Operating Area.
1
D = 0.5
0.5
R (t) = r(t) * R
θ
0.2
0.1
0.05
0.02
r(t), NORMALIZED EFFECTIVE
0.01
TRANSIENT THERMAL RESISTANCE
0.005
0.00001 0.0001 0.001 0.01 0.1 1 10 100 300
0.2
0.1
0.05
0.02
0.01
Single Pulse
t , TIME (sec)
1
JA
R = See Note 2a
θJA
P(pk)
t 1
t 2
T - T = P * R (t)
J
A
Duty Cycle, D = t / t1 2
θ
θ
JA
JA
Figure 13. Transient Thermal Response Curve.
Note: Thermal characterization performed on the conditions described in Note
2a. Transient thermal response will change depends on the circuit board
FDC6324L Rev. D
FDC6324L Load Switch Application
APPLICATION CIRCUIT
Q2
IN OUT
R1
ON/OFF
Q1
R2
C1
LOADCo
Component Values
R1 Typical 10k - 1MΩ
R2 Typical 0 - 10kΩ (optional)
C1 Typical 1000pF (optional)
Design Notes
R1 is needed to turn off Q2.
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
SuperSOTTM-6 package.
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.
R2 can be used to soft start the switch in the case the output capacitance Co is small.
R2 ≤ should be at least 10 times smaller than R1 to guarantee Q1 turns on.
By using R1 and R2 a certain amount of current is lost from the input. This bias current loss is given by
the equation
BIAS _LOSS
R2 and C
Vin
=
R 1 +R2
of Q2 make ramp for slow turn on. If excessive overshoot current occurs due to fast turn on,
RSS
when the switch is ON. I
BIAS_LOSS
can be minimized by large R1.I
additional capacitance C1 can be added externally to slow down the turn on.
FDC6324L Rev. D
TRADEMARKS
The following are registered and unregistered trademarks Fairchild Semiconductor owns or is authorized to use and is
not intended to be an exhaustive list of all such trademarks.
ACEx™
CoolFET™
CROSSVOLT™
2
E
CMOS
TM
FACT™
FACT Quiet Series™
®
FAST
FASTr™
GTO™
HiSeC™
ISOPLANAR™
MICROWIRE™
POP™
PowerTrench™
QFET™
QS™
Quiet Series™
SuperSOT™-3
SuperSOT™-6
SuperSOT™-8
TinyLogic™
UHC™
VCX™
DISCLAIMER
FAIRCHILD SEMICONDUCTOR RESERVES THE RIGHT TO MAKE CHANGES WITHOUT FURTHER
NOTICE TO ANY PRODUCTS HEREIN TO IMPROVE RELIABILITY, FUNCTION OR DESIGN. FAIRCHILD
DOES NOT ASSUME ANY LIABILITY ARISING OUT OF THE APPLICA TION OR USE OF ANY PRODUCT
OR CIRCUIT DESCRIBED HEREIN; NEITHER DOES IT CONVEY ANY LICENSE UNDER ITS PATENT
RIGHTS, NOR THE RIGHTS OF OTHERS.
LIFE SUPPORT POLICY
FAIRCHILD’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT
DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROV AL OF FAIRCHILD SEMICONDUCTOR CORPORA TION.
As used herein:
1. Life support devices or systems are devices or
systems which, (a) are intended for surgical implant into
the body, or (b) support or sustain life, or (c) whose
failure to perform when properly used in accordance
with instructions for use provided in the labeling, can be
reasonably expected to result in significant injury to the
user.
2. A critical component is any component of a life
support device or system whose failure to perform can
be reasonably expected to cause the failure of the life
support device or system, or to affect its safety or
effectiveness.
PRODUCT STA TUS DEFINITIONS
Definition of Terms
Datasheet Identification Product Status Definition
Advance Information
Preliminary
No Identification Needed
Obsolete
Formative or
In Design
First Production
Full Production
Not In Production
This datasheet contains the design specifications for
product development. Specifications may change in
any manner without notice.
This datasheet contains preliminary data, and
supplementary data will be published at a later date.
Fairchild Semiconductor reserves the right to make
changes at any time without notice in order to improve
design.
This datasheet contains final specifications. Fairchild
Semiconductor reserves the right to make changes at
any time without notice in order to improve design.
This datasheet contains specifications on a product
that has been discontinued by Fairchild semiconductor.
The datasheet is printed for reference information only.
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