March 2000
PRELIMINARY
1999 Fairchild Semiconductor Corporation
FDS6982S Rev B(W)
FDS6982S
Dual Notebook Power Supply N-Channel PowerTrench
SyncFet
TM
General Description
The FDS6982S 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. FDS6982S 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 an integrated Schottky diode
using Fairchild's monolithic SyncFET technology.
Features
Q2:
Optimized to minimize conduction losses
Includes SyncFET Schottky body diode
8.6A, 30V
R
DS(on)
= 0.016
@ V
GS
= 10V
R
DS(on)
= 0.021
@ V
GS
= 4.5V
Q1:
Optimized for low switching losses
Low Gate Charge ( 8.5 nC typical)
6.3A, 30V
R
DS(on)
= 0.028
@ V
GS
= 10V
R
DS(on)
= 0.035
@ 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)
8.6
6.3
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
FDS6982S
FDS6982S
13"
12mm
2500 units
FDS6982S
FDS6982S Rev B (W)
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 uA
Q2
Q1
30
30
V
BV
DSS
T
J
Breakdown Voltage
Temperature Coefficient
I
D
= 1 mA, Referenced to 25
C
I
D
= 250 A, Referenced to 25
C
Q2
Q1
20
26
mV/
C
I
DSS
Zero Gate Voltage Drain
Current
V
DS
= 24 V, V
GS
= 0 V
Q2
Q1
1000
1
A
I
GSSF
Gate-Body Leakage, Forward
V
GS
= 20 V, V
DS
= 0 V
All
100
nA
I
GSSR
Gate-Body Leakage, Reverse 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
3
3
V
V
GS(th)
T
J
Gate Threshold Voltage
Temperature Coefficient
I
D
= 1 mA, Referenced to 25
C
I
D
= 250 A, Referenced to 25
C
Q2
Q1
-3.5
-5
mV/
C
R
DS(on)
Static Drain-Source
On-Resistance
V
GS
= 10 V, I
D
= 8.6 A
V
GS
= 10 V, I
D
= 8.6 A, T
J
= 125
C
V
GS
= 4.5 V, I
D
= 7.5 A
V
GS
= 10 V, I
D
= 6.3 A
V
GS
= 10 V, I
D
= 6.3 A, T
J
= 125
C
V
GS
= 4.5 V, I
D
= 5.6 A
Q2
Q1
0.013
0.020
0.017
0.021
0.038
0.028
0.016
0.027
0.021
0.028
0.047
0.035
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
= 8.6 A
V
DS
= 5 V, I
D
= 6.3 A
Q2
Q1
38
18
S
Dynamic Characteristics
C
iss
Input Capacitance
Q2
Q1
2040
815
pF
C
oss
Output Capacitance
Q2
Q1
615
186
pF
C
rss
Reverse Transfer Capacitance
V
DS
= 10 V, V
GS
= 0 V,
f = 1.0 MHz
Q2
Q1
216
66
pF
FDS6982S
FDS6982S Rev B (W)
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
10
10
18
18
ns
t
r
Turn-On Rise Time
Q2
Q1
10
14
18
25
ns
t
d(off)
Turn-Off Delay Time
Q2
Q1
34
21
55
34
ns
t
f
Turn-Off Fall Time
V
DD
= 15 V, I
D
= 1 A,
V
GS
= 10V, R
GEN
= 6
Q2
Q1
14
7
23
14
ns
Q
g
Total Gate Charge
Q2
Q1
17.5
8.5
26
12
nC
Q
gs
Gate-Source Charge
Q2
Q1
6.3
2.4
nC
Q
gd
Gate-Drain Charge
Q2
V
DS
= 15 V, I
D
= 11.5 A, V
GS
= 5 V
Q1
V
DS
= 15 V, I
D
= 6.3 A,V
GS
= 5 V
Q2
Q1
5.4
3.1
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
20
ns
Q
RR
Reverse Recovery Charge
I
F
= 11.5A,
d
iF
/d
t
= 300 A/s
(Note 3)
Q2
19.7
nC
V
SD
Drain-Source Diode Forward
Voltage
V
GS
= 0 V, I
S
= 3 A
(Note
2)
V
GS
= 0 V, I
S
= 6 A
(Note
2)
V
GS
= 0 V, I
S
= 1.3 A
(Note
2)
Q2
Q2
Q1
0.42
0.56
0.70
.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) 78/W when
mounted on a
0.5 in
2
pad of 2 oz
copper
b) 125/W when
mounted on a .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%
3. See "SyncFET Schottky body diode characteristics" below.
FDS6982S Rev B (W)
Typical Characteristics: Q2
0
10
20
30
40
50
0
0.5
1
1.5
2
2.5
V
DS
, DRAIN-SOURCE VOLTAGE (V)
I
D
, DRAIN CURRENT (A)
4.0V
6.0V
3.0V
4.5V
V
GS
= 10V
3.5V
5.0V
0.5
1
1.5
2
2.5
0
10
20
30
40
50
I
D
, DRAIN CURRENT (A)
R
DS(ON)
, NORMALIZED
DRAIN-SOURCE ON-RESISTANCE
V
GS
= 3.0V
3.5V
4.0V
4.5V
6.0V
10V
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
= 11.5A
V
GS
= 10V
0.01
0.015
0.02
0.025
0.03
0.035
0.04
2
4
6
8
10
V
GS
, GATE TO SOURCE VOLTAGE (V)
R
DS(ON)
, ON-RESISTANCE (OHM)
I
D
= 11.5 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
10
20
30
40
50
1
2
3
4
5
V
GS
, GATE TO SOURCE VOLTAGE (V)
I
D
, DRAIN CURRENT (A)
T
A
= -55
o
C
100
o
V
DS
= 5V
25
o
C
0.01
0.1
1
10
0
0.2
0.4
0.6
0.8
V
SD
, BODY DIODE FORWARD VOLTAGE (V)
I
S
, REVERSE DRAIN CURRENT (A)
T
A
= 100
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.
FDS6982S
FDS6982S Rev B (W)
Typical Characteristics: Q2
0
2
4
6
8
10
0
10
20
30
40
Q
g
, GATE CHARGE (nC)
V
GS
, GATE-SOURCE VOLTAGE (V)
I
D
= 11.5A
V
DS
= 5V
15V
10V
0
500
1000
1500
2000
2500
3000
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
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), 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.
FDS6982S
PDF 
ZIP