www.docs.chipfind.ru
June 2005
2005 Fairchild Semiconductor Corporation
FDS6984AS Rev A(X)
FDS6984AS
Dual Notebook Power Supply N-Channel PowerTrench
SyncFET
TM
General Description
The FDS6984AS is designed to replace two single
SO-8 MOSFETs and Schottky diode in synchronous
DC:DC power supplies that provide various peripheral
voltages for notebook computers and other battery
powered electronic devices. FDS6984AS contains two
unique 30V, N-channel, logic level, PowerTrench
MOSFETs designed to maximize power conversion
efficiency.
The high-side switch (Q1) is designed with specific
emphasis on reducing switching losses while the low-
side switch (Q2) is optimized to reduce conduction
losses. Q2 also includes a patented combination of a
MOSFET monolithically integrated with a Schottky
diode.
Features
Q2:
Optimized to minimize conduction losses
Includes SyncFET Schottky diode
8.5A, 30V R
DS(on)
max= 20 m
@ V
GS
= 10V
R
DS(on)
max= 28 m
@ V
GS
= 4.5V
Q1:
Optimized for low switching losses
Low gate charge (8nC typical)
5.5A, 30V R
DS(on)
max= 31 m
@ V
GS
= 10V
R
DS(on)
max= 40 m
@ V
GS
= 4.5V
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
= 25C unless otherwise noted
Symbol Parameter
Q2
Q1 Units
V
DSS
Drain-Source
Voltage
30
30
V
V
GSS
Gate-Source
Voltage
20
20
V
I
D
Drain Current - Continuous
(Note 1a)
8.5
5.5 A
-
Pulsed
30
20
P
D
Power Dissipation for Dual Operation
2
W
Power Dissipation for Single Operation
(Note 1a)
1.6
(Note 1b)
1
(Note 1c)
0.9
T
J
, T
STG
Operating and Storage Junction Temperature Range
55 to +150
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
FDS6984AS FDS6984AS 13"
12mm
2500
units
FDS6984AS FDS6984AS_NL
(Note 4)
13"
12mm
2500
units
FDS6984AS
FDS6984AS Rev A (X)
Electrical Characteristics
T
A
= 25C unless otherwise noted
Symbol
Parameter Test
Conditions
Type
Min
Typ Max Units
Off Characteristics
BV
DSS
Drain-Source Breakdown
Voltage
V
GS
= 0 V, I
D
= 1 mA
V
GS
= 0 V, I
D
= 250 A
Q2
Q1
30
30
V
V
DS
= 24 V, V
GS
= 0 V
Q2
Q1
500
1
A
Q2 2.3 mA
I
DSS
Zero Gate Voltage Drain
Current
V
DS
= 24 V, V
GS
= 0 V, T
J
= 125
C
Q1 79 nA
I
GSS
Gate-Body
Leakage
V
GS
=
20 V, V
DS
= 0 V
All
100
nA
On Characteristics
(Note 2)
V
GS(th)
Gate Threshold Voltage
V
DS
= V
GS
, I
D
= 1 mA
V
DS
= V
GS
, I
D
= 250 A
Q2
Q1
1
1
1.7
1.8
3
3
V
V
GS(th)
T
J
Gate Threshold Voltage
Temperature Coefficient
I
D
= 1 mA, Referenced to 25
C
I
D
= 250 uA, Referenced to 25
C
Q2
Q1
3
4
mV/
C
V
GS
= 10 V, I
D
= 8.5 A
V
GS
= 10 V, I
D
= 8.5 A, T
J
= 125
C
V
GS
= 4.5 V, I
D
= 7 A
Q2
17
24
21
20
32
28
R
DS(on)
Static Drain-Source
On-Resistance
V
GS
= 10 V, I
D
= 5.5 A
V
GS
= 10 V, I
D
= 5.5 A, T
J
= 125
C
V
GS
= 4.5 V, I
D
= 4.6 A
Q1 26
34
32
31
43
40
m
I
D(on)
On-State
Drain
Current V
GS
= 10 V, V
DS
= 5 V
Q2
Q1
30
20
A
g
FS
Forward
Transconductance
V
DS
= 5 V, I
D
= 8.5 A
V
DS
= 5 V, I
D
= 5.5 A
Q2
Q1
25
18
S
Dynamic Characteristics
C
iss
Input
Capacitance
Q2
Q1
530
420
pF
C
oss
Output
Capacitance
Q2
Q1
170
120
pF
C
rss
Reverse Transfer Capacitance
V
DS
= 15 V, V
GS
= 0 V,
f = 1.0 MHz
Q2
Q1
60
50
pF
R
G
Gate
Resistance
V
GS
= 15mV, f = 1.0 MHz
Q2
Q1
3.1
2.2
FDS6984
A
S
FDS6984AS Rev A (X)
Electrical Characteristics
(continued)
T
A
= 25C unless otherwise noted
Symbol
Parameter Test
Conditions
Type
Min
Typ Max Units
Switching Characteristics
(Note 2)
t
d(on)
Turn-On Delay Time
Q2
Q1
8
9
16
18
ns
t
r
Turn-On
Rise
Time
Q2
Q1
5
6
10
12
ns
t
d(off)
Turn-Off Delay Time
Q2
Q1
23
22
37
35
ns
t
f
Turn-Off
Fall
Time
V
DD
= 15 V, I
D
= 1 A,
V
GS
= 10V, R
GEN
= 6
Q2
Q1
4
2
8
4
ns
t
d(on)
Turn-On Delay Time
Q2
Q1
9
10
18
19
ns
t
r
Turn-On
Rise
Time
Q2
Q1
7
11
14
20
ns
t
d(off)
Turn-Off Delay Time
Q2
Q1
13
13
24
24
ns
t
f
Turn-Off
Fall
Time
V
DD
= 15 V, I
D
= 1 A,
V
GS
= 4.5V, R
GEN
= 6
Q2
Q1
4
3
8
6
ns
Q
g(TOT)
Total Gate Charge, Vgs = 10V
Q2
Q1
10
8
14
11
nC
Q
g
Total Gate Charge, Vgs = 5V
Q2
Q1
5
4
8
6
nC
Q
gs
Gate-Source
Charge
Q2
Q1
1.5
1.3
nC
Q
gd
Gate-Drain
Charge
Q2:
V
DS
= 15 V, I
D
= 8.5 A
Q1:
V
DS
= 15 V, I
D
= 5.5 A
Q2
Q1
1.9
1.5
nC
DrainSource Diode Characteristics and Maximum Ratings
I
S
Maximum Continuous Drain-Source Diode Forward Current
Q2
Q1
3.0
1.3
A
t
rr
Reverse
Recovery
Time
13
ns
Q
rr
Reverse Recovery Charge
I
F
= 10A,
dI
F
/dt = 300 A/s
(Note
3)
Q2
6 nC
t
rr
Reverse
Recovery
Time
17
ns
Q
rr
Reverse Recovery Charge
I
F
= 5.5A,
dI
F
/dt = 100 A/s
(Note 3)
Q1
6 nC
V
SD
Drain-Source Diode Forward
Voltage
V
GS
= 0 V, I
S
= 2.3 A
(Note 2)
V
GS
= 0 V, I
S
= 1.3 A
(Note 2)
Q2
Q1
0.6
0.8
0.7
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
0.5in
2
pad of 2
oz copper
b) 125C/W
when
mounted on a
0.02 in
2
pad of
2 oz copper
c) 135C/W
when
mounted on a
minimum pad.
Scale 1 : 1 on letter size paper
2. See "SyncFET Schottky body diode characteristics" below.
3. Pulse Test: Pulse Width < 300
s, Duty Cycle < 2.0%
4. FDS6984AS_NL is a lead free product. The FDS6984AS_NL marking will appear on the reel label.
FDS6984
A
S
FDS6984AS Rev A (X)
Typical Characteristics: Q2
0
5
10
15
20
25
30
0
0.5
1
1.5
2
2.5
3
V
DS
, DRAIN-SOURCE VOLTAGE (V)
I
D
, DRAI
N
C
URRE
NT
(A
)
3.0V
4.5V
4.0V
3.5V
V
GS
= 10V
6.0V
2.5V
0.8
1
1.2
1.4
1.6
1.8
2
0
5
10
15
20
25
30
I
D
, DRAIN CURRENT (A)
R
DS
(O
N)
,
NO
R
M
ALI
Z
ED
DR
AI
N
-
SO
UR
CE
O
N
-
R
E
S
I
S
T
AN
CE
V
GS
= 3.0V
6.0V
3.5V
10V
5.0V
4.5V
4.0V
Figure 1. On-Region Characteristics.
Figure 2. On-Resistance Variation with
Drain Current and Gate Voltage.
0.7
0.85
1
1.15
1.3
1.45
1.6
-50
-25
0
25
50
75
100
125
150
T
J
, JUNCTION TEMPERATURE (
o
C)
R
DS
(O
N)
,
NO
RMAL
I
Z
E
D
DR
AI
N
-
S
O
UR
CE
O
N
-
R
E
S
I
S
T
AN
CE
I
D
= 8.5A
V
GS
= 10V
0.01
0.02
0.03
0.04
0.05
0.06
2
4
6
8
10
V
GS
, GATE TO SOURCE VOLTAGE (V)
R
DS
(O
N)
, ON
-R
ES
IST
A
N
C
E
(
O
HM
)
I
D
= 4.25A
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
25
30
1
1.5
2
2.5
3
3.5
4
V
GS
, GATE TO SOURCE VOLTAGE (V)
I
D
, DRAI
N
C
URRE
NT (A)
T
A
= 125
o
C
25
o
C
-55
o
C
V
DS
= 5V
0.001
0.01
0.1
1
10
100
0
0.2
0.4
0.6
0.8
1
V
SD
, BODY DIODE FORWARD VOLTAGE (V)
I
S
, REVER
SE DR
AIN
CU
RR
EN
T
(
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.
FDS6984
A
S
FDS6984AS Rev A (X)
Typical Characteristics: Q2
0
2
4
6
8
10
0
2
4
6
8
10
12
Q
g
, GATE CHARGE (nC)
V
GS
,
G
A
T
E
-
S
O
URCE
VO
L
T
A
G
E
(
V
)
I
D
=8.5A
V
DS
= 10V
15V
20V
0
200
400
600
800
0
5
10
15
20
25
30
V
DS
, DRAIN TO SOURCE VOLTAGE (V)
CA
PAC
I
TAN
C
E
(
p
F)
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
,
DR
AI
N
CU
R
R
EN
T (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
A
K
TR
AN
SI
EN
T P
O
W
E
R
(W
)
SINGLE PULSE
R
JA
= 135C/W
T
A
= 25C
Figure 9. Maximum Safe Operating Area.
Figure 10. Single Pulse Maximum
Power Dissipation.
FDS6984
A
S
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