May 2001
2001 Fairchild Semiconductor Corporation
FDS3812 Rev B1(W)
FDS3812
80V N-Channel Dual PowerTrench
MOSFET
General Description
This N-Channel MOSFET has been designed
specifically to improve the overall efficiency of DC/DC
converters using either synchronous or conventional
switching PWM controllers.
These MOSFETs feature faster switching and lower
gate charge than other MOSFETs with comparable
R
DS(ON)
specifications. The result is a MOSFET that is
easy and safer to drive (even at very high frequencies),
and DC/DC power supply designs with higher overall
efficiency.
Features
3.4 A, 80 V.
R
DS(ON)
= 74 m
@ V
GS
= 10 V
R
DS(ON)
= 84 m
@ V
GS
= 6 V
Fast switching speed
Low gate charge (13nC typ)
High performance trench technology for extremely
low R
DS(ON)
High power and current handling capability
S2
SO-8
G2
S1
G1
D2
D2
D1
D1
4
3
2
1
5
6
7
8
Q1
Q2
Absolute Maximum Ratings
T
A
=25
o
C unless otherwise noted
Symbol Parameter
Ratings
Units
V
DSS
Drain-Source
Voltage
80
V
V
GSS
Gate-Source
Voltage
20
V
I
D
Drain Current Continuous
(Note 1a)
3.4 A
Pulsed
20
P
D
Power Dissipation for Dual Operation
2
W
Power Dissipation for Single Operation
(Note 1a)
1.6
(Note 1b)
1.0
(Note 1c)
0.9
T
J
, T
STG
Operating and Storage Junction Temperature Range
55 to +175
C
Thermal Characteristics
R
JA
Thermal Resistance, Junction-to-Ambient
(Note 1a)
78
C/W
R
JC
Thermal Resistance, Junction-to-Case
(Note 1)
40
C/W
Package Marking and Ordering Information
Device Marking
Device
Reel Size
Tape width
Quantity
FDS3812 FDS3812 13''
12mm
2500
units
FDS3812
FDS3812 Rev B1(W)
Electrical Characteristics
T
A
= 25C unless otherwise noted
Symbol Parameter
Test
Conditions
Min
Typ
Max
Units
Drain-Source Avalanche Ratings
(Note 2)
W
DSS
Single
Pulse
Drain-Source
Avalanche Energy
V
DD
= 40 V, I
D
= 3.4 A
90
mJ
I
AR
Maximum Drain-Source Avalanche
Current
3.4 A
Off Characteristics
BV
DSS
DrainSource Breakdown Voltage
V
GS
= 0 V, I
D
= 250
A
80 V
BV
DSS
T
J
Breakdown Voltage Temperature
Coefficient
I
D
= 250
A, Referenced to 25
C
80
mV/
C
I
DSS
Zero Gate Voltage Drain Current
V
DS
= 64 V,
V
GS
= 0 V
1
A
I
GSSF
GateBody
Leakage,
Forward V
GS
= 20 V,
V
DS
= 0 V
100
nA
I
GSSR
GateBody
Leakage,
Reverse V
GS
= 20 V
V
DS
= 0 V
100
nA
On Characteristics
(Note 2)
V
GS(th)
Gate Threshold Voltage
V
DS
= V
GS
, I
D
= 250
A
2 2.4 4 V
V
GS(th)
T
J
Gate Threshold Voltage
Temperature Coefficient
I
D
= 250
A, Referenced to 25
C
6
mV/
C
R
DS(on)
Static
DrainSource
OnResistance
V
GS
= 10 V,
I
D
= 3.4 A
V
GS
= 6.0 V,
I
D
= 3.2 A
V
GS
= 10 V, I
D
= 3.4 A, T
J
= 125
C
53
58
94
74
84
140
m
I
D(on)
OnState
Drain
Current
V
GS
= 10 V,
V
DS
= 5 V
20
A
g
FS
Forward
Transconductance V
DS
= 10 V,
I
D
= 3.4 A
14
S
Dynamic Characteristics
C
iss
Input
Capacitance
634
pF
C
oss
Output
Capacitance
58 pF
C
rss
Reverse Transfer Capacitance
V
DS
= 40 V,
V
GS
= 0 V,
f = 1.0 MHz
28 pF
Switching Characteristics
(Note 2)
t
d(on)
TurnOn Delay Time
7
14
ns
t
r
TurnOn Rise Time
3
6
ns
t
d(off)
TurnOff Delay Time
24
28
ns
t
f
TurnOff Fall Time
V
DD
=40 V,
I
D
= 1 A,
V
GS
= 10 V,
R
GEN
= 6
4 8 ns
Q
g
Total Gate Charge
13
18
nC
Q
gs
GateSource
Charge
2.4
nC
Q
gd
GateDrain
Charge
V
DS
= 40 V,
I
D
= 3.4 A,
V
GS
= 10 V
2.8 nC
DrainSource Diode Characteristics and Maximum Ratings
I
S
Maximum Continuous DrainSource Diode Forward Current
1.3
A
V
SD
DrainSource Diode Forward
Voltage
V
GS
= 0 V, I
S
= 1.3 A
(Note 2)
0.8
1.2
V
Notes:
1. R
JA
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
JC
is guaranteed by design while R
CA
is determined by the user's board design.
a) 78C/W when
mounted on a 1in
2
pad of 2 oz copper
b) 125C/W when
mounted on a .04 in
2
pad of 2 oz copper
c) 135C/W when mounted on a
minimum pad.
2. Pulse Test: Pulse Width < 300
s, Duty Cycle < 2.0%
FDS3812
FDS3812 Rev B1(W)
Typical Characteristics
0
5
10
15
20
0
1
2
3
4
5
V
DS
, DRAIN-SOURCE VOLTAGE (V)
I
D
, DRAIN CURRE
NT (
A
)
5.0V
4.0V
4.5V
V
GS
= 10V
6.0V
0.8
1
1.2
1.4
1.6
1.8
0
5
10
15
20
I
D
, DRAIN CURRENT (A)
R
DS
(
O
N)
, NO
RMALIZE
D
DRAIN-
S
O
URCE
O
N
-
R
E
S
I
S
T
ANCE
V
GS
= 4.0V
4.5V
5.0V
10V
6.0V
Figure 1. On-Region Characteristics.
Figure 2. On-Resistance Variation with
Drain Current and Gate Voltage.
0.4
0.7
1
1.3
1.6
1.9
2.2
2.5
-50
-25
0
25
50
75
100
125
150
175
T
J
, JUNCTION TEMPERATURE (
o
C)
R
DS
(
O
N)
, NO
RMALIZE
D
DRAIN-
S
O
URCE
O
N
-
R
E
S
I
S
T
ANC
E
I
D
= 3.4A
V
GS
=10V
0.02
0.06
0.1
0.14
0.18
2
4
6
8
10
V
GS
, GATE TO SOURCE VOLTAGE (V)
R
DS
(
O
N)
, O
N
-
R
E
S
I
S
T
ANCE
(
O
HM)
I
D
= 1.7 A
T
A
= 125
o
C
T
A
= 25
o
C
Figure 3. On-Resistance Variation with
Temperature.
Figure 4. On-Resistance Variation with
Gate-to-Source Voltage.
0
5
10
15
20
2
3
4
5
V
GS
, GATE TO SOURCE VOLTAGE (V)
I
D
, DRAIN CURRE
NT (
A
)
T
A
= 125
o
C
-55
o
C
V
DS
= 5V
25
o
C
0.0001
0.001
0.01
0.1
1
10
100
0
0.2
0.4
0.6
0.8
1
1.2
V
SD
, BODY DIODE FORWARD VOLTAGE (V)
I
S
,
R
EVER
SE
DRAIN CURRE
NT (
A
)
T
A
= 125
o
C
25
o
C
-55
o
C
V
GS
= 0V
Figure 5. Transfer Characteristics.
Figure 6. Body Diode Forward Voltage Variation
with Source Current and Temperature.
FDS3812
FDS3812 Rev B1(W)
Typical Characteristics
0
2
4
6
8
10
0
3
6
9
12
15
Q
g
, GATE CHARGE (nC)
V
GS
, G
A
TE
-
S
O
URCE
V
O
LTAG
E
(
V
)
I
D
= 3.4A
V
DS
= 20V
60V
40V
0
200
400
600
800
1000
0
20
40
60
80
-V
DS
, DRAIN TO SOURCE VOLTAGE (V)
CAP
ACITANCE
(
pF)
C
ISS
C
RSS
C
OSS
f = 1MHz
V
GS
= 0 V
Figure 7. Gate Charge Characteristics.
Figure 8. Capacitance Characteristics.
0.01
0.1
1
10
100
0.1
1
10
100
1000
V
DS
, DRAIN-SOURCE VOLTAGE (V)
I
D
, DRAIN CURRE
NT (
A
)
DC
10s
1s
100ms
100
s
R
DS(ON)
LIMIT
V
GS
= 10V
SINGLE PULSE
R
JA
= 135
o
C/W
T
A
= 25
o
C
10ms
1ms
0
10
20
30
40
50
0.001
0.01
0.1
1
10
100
1000
t
1
, TIME (sec)
P
(
pk
)
,
P
E
AK TRANS
IE
NT P
O
WE
R (
W
)
SINGLE PULSE
R
JA
= 135C/W
T
A
= 25C
Figure 9. Maximum Safe Operating Area.
Figure 10. Single Pulse Maximum
Power Dissipation.
0.001
0.01
0.1
1
0.0001
0.001
0.01
0.1
1
10
100
1000
t
1
, TIME (sec)
r(t), NORMALIZED EFFECTIVE
TRANSIENT THERMAL RESISTANCE
R
JA
(t) = r(t) + R
JA
R
JA
= 135C/W
T
J
- T
A
= P * R
JA
(t)
Duty Cycle, D = t
1
/ t
2
P(pk
)
t
1
t
2
SINGLE PULSE
0.01
0.02
0.05
0.1
0.2
D = 0.5
Figure 11. Transient Thermal Response Curve.
Thermal characterization performed using the conditions described in Note 1c.
Transient thermal response will change depending on the circuit board design.
FDS3812
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.
LIFE SUPPORT POLICY
FAIRCHILD'S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT
DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF FAIRCHILD SEMICONDUCTOR CORPORATION.
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 STATUS DEFINITIONS
Definition of Terms
Datasheet Identification
Product Status
Definition
Advance Information
Preliminary
No Identification Needed
Obsolete
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.
Formative or
In Design
First Production
Full Production
Not In Production
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 APPLICATION OR USE OF ANY PRODUCT
OR CIRCUIT DESCRIBED HEREIN; NEITHER DOES IT CONVEY ANY LICENSE UNDER ITS PATENT
RIGHTS, NOR THE RIGHTS OF OTHERS.
OPTOPLANARTM
PACMANTM
POPTM
PowerTrench
QFETTM
QSTM
QT OptoelectronicsTM
Quiet SeriesTM
SILENT SWITCHER
SMART STARTTM
StealthTM
FAST
FASTrTM
FRFETTM
GlobalOptoisolatorTM
GTOTM
HiSeCTM
ISOPLANARTM
LittleFETTM
MicroFETTM
MICROWIRETM
OPTOLOGICTM
Rev. H2
ACExTM
BottomlessTM
CoolFETTM
CROSSVOLTTM
DenseTrenchTM
DOMETM
EcoSPARKTM
E
2
CMOS
TM
EnSigna
TM
FACTTM
FACT Quiet SeriesTM
SuperSOTTM-3
SuperSOTTM-6
SuperSOTTM-8
SyncFETTM
TinyLogicTM
UHCTM
UltraFET
VCXTM
PDF 
ZIP