February 2001
2001 Fairchild Semiconductor Corporation
FDS9945 Rev B(W)
FDS9945
60V N-Channel PowerTrench
MOSFET
General Description
These N Channel Logic Level MOSFET have been
designed specifically to improve the overall efficiency of
DC/DC converters using either synchronous or
conventional switching PWM controllers.
The MOSFET feature faster switching and lower gate
charge than other MOSFET with comparable RDS(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
3.5 A, 60 V. R
DS(ON)
= 0.100
@ V
GS
= 10 V
R
DS(ON)
= 0.200
@ V
GS
= 4.5V
Optimized for use in switching DC/DC converters
with PWM controllers
Very fast switching
Low gate charge.
S
D
S
S
SO-8
D
D
D
G
D2
D2
D1
D1
S2
G2
S1
G1
Pin 1
SO-8
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
60
V
V
GSS
Gate-Source Voltage
20
V
I
D
Drain Current Continuous
(Note 1a)
3.5
A
Pulsed
10
Power Dissipation for Single Operation
(Note 1a)
2
(Note 1b)
1.6
P
D
(Note 1c)
1.0
W
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 (steady state), 50 (10 sec)
C/W
R
JA
Thermal Resistance, Junction-to-Ambient
(Note 1c)
135
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
FDS9945
FDS9945
13''
12mm
2500 units
FDS9945
FDS9945 Rev B(W)
Electrical Characteristics
T
A
= 25C unless otherwise noted
Symbol
Parameter
Test Conditions
Min Typ Max Units
Off Characteristics
BV
DSS
DrainSource Breakdown Voltage V
GS
= 0 V, I
D
= 250
A
60
V
BV
DSS
T
J
Breakdown Voltage Temperature
Coefficient
I
D
= 250
A, Referenced to 25
C
62.5
mV/
C
I
DSS
Zero Gate Voltage Drain Current
V
DS
= 48 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
1
2.5
3
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
= 3.5 A
V
GS
= 4.5V,
I
D
= 2.5 A
V
GS
= 10 V, I
D
=3.5A, T
J
=125
C
74
103
126
100
200
170
m
I
D(on)
OnState Drain Current
V
GS
= 10 V,
= V
DS
=30 V
10
A
g
FS
Forward Transconductance
V
DS
= 5V,
I
D
= 3.5 A
8.6
S
Dynamic Characteristics
C
iss
Input Capacitance
420
pF
C
oss
Output Capacitance
48
pF
C
rss
Reverse Transfer Capacitance
V
DS
= 30 V,
V
GS
= 0 V,
f = 1.0 MHz
20
pF
Switching Characteristics
(Note 2)
t
d(on)
TurnOn Delay Time
7
14
ns
t
r
TurnOn Rise Time
4.3
8.6
ns
t
d(off)
TurnOff Delay Time
19
34
ns
t
f
TurnOff Fall Time
V
DD
= 30 V,
I
D
= 1 A,
V
GS
= 10 V,
R
GEN
= 6
3
6
ns
Q
g
Total Gate Charge
8
13
nC
Q
gs
GateSource Charge
4
nC
Q
gd
GateDrain Charge
V
DS
= 30 V,
I
D
= 3.5 A,
V
GS
= 5 V
2.5
nC
DrainSource Diode Characteristics and Maximum Ratings
I
S
Maximum Continuous DrainSource Diode Forward Current
2.1
A
V
SD
DrainSource Diode Forward
Voltage
V
GS
= 0 V, I
S
= 2.1 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) 78/W when
mounted on a 0.5in
2
pad of 2 oz copper
b) 125/W when
mounted on a 0.02
in
2
pad of 2 oz
copper
c) 135/W when mounted on a
minimum pad.
Scale 1 : 1 on letter size paper
2. Pulse Test: Pulse Width < 300
s, Duty Cycle < 2.0%
FDS9945
FDS9945 Rev B(W)
Typical Characteristics
0
5
10
15
20
0
1
2
3
4
5
V
DS
, DRAIN-SOURCE VOLTAGE (V)
I
D
, DRAIN CURRENT (A)
5.0V
4.0V
4.5V
6.0V
V
GS
= 10V
0.8
1
1.2
1.4
1.6
1.8
2
2.2
0
3
6
9
12
15
I
D
, DRAIN CURRENT (A)
R
DS(ON)
, NORMALIZED
DRAIN-SOURCE ON-RESISTANCE
V
GS
= 4.0V
5.0V
6.0V
10V
4.5V
Figure 1. On-Region Characteristics.
Figure 2. On-Resistance Variation with
Drain Current and Gate Voltage.
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
2
-50
-25
0
25
50
75
100
125
150
T
J
, JUNCTION TEMPERATURE (
o
C)
R
DS(ON)
, NORMALIZED
DRAIN-SOURCE ON-RESISTANCE
I
D
= 3.5A
V
GS
= 10V
0.05
0.1
0.15
0.2
0.25
2
4
6
8
10
V
GS
, GATE TO SOURCE VOLTAGE (V)
R
DS(ON)
, ON-RESISTANCE (OHM)
I
D
= 1.75A
T
A
= 125
o
C
T
A
= 25
o
C
Figure 3. On-Resistance Variation
withTemperature.
Figure 4. On-Resistance Variation with
Gate-to-Source Voltage.
0
2
4
6
8
10
2
2.5
3
3.5
4
4.5
5
V
GS
, GATE TO SOURCE VOLTAGE (V)
I
D
, DRAIN CURRENT (A)
T
A
= -55
o
C
25
o
C
125
o
C
V
D S
= 5V
0.0001
0.001
0.01
0.1
1
10
0
0.2
0.4
0.6
0.8
1
1.2
V
SD
, BODY DIODE FORWARD VOLTAGE (V)
I
S
, REVERSE DRAIN CURRENT (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.
FDS9945
FDS9945 Rev B(W)
Typical Characteristics
0
2
4
6
8
10
0
4
8
12
16
Q
g
, GATE CHARGE (nC)
V
GS
, GATE-SOURCE VOLTAGE (V)
I
D
= 3.5A
V
D S
= 20V
40V
30V
0
100
200
300
400
500
600
0
5
10
15
20
25
30
V
DS
, DRAIN TO SOURCE VOLTAGE (V)
CAPACITANCE (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
V
DS
, DRAIN-SOURCE VOLTAGE (V)
I
D
, DRAIN CURRENT (A)
DC
10s
1s
100ms
R
DS(ON)
LIMIT
V
GS
= 10V
SINGLE PULSE
R
JA
= 135
o
C/W
T
A
= 25
o
C
10ms
1ms
100s
0
10
20
30
40
50
0.001
0.01
0.1
1
10
100
t
1
, TIME (sec)
P(pk), PEAK TRANSIENT POWER (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
J A
= 135 C/W
T
J
- T
A
= P * R
J A
(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.
FDS9945
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.
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