Symbol
V
DS
V
GS
5.8554
I
DM
T
J
, T
STG
Symbol
Typ
Max
48
62.5
74
110
R
JL
35
40
Absolute Maximum Ratings T
A
=25C unless otherwise noted
Parameter
Maximum
Units
Drain-Source Voltage
30
V
Gate-Source Voltage
20
V
A
T
A
=70C
5.8
Pulsed Drain Current
B
30
Continuous Drain
Current
A
T
A
=25C
I
D
6.9
T
A
=70C
1.44
W
Power Dissipation
T
A
=25C
P
D
2
Steady-State
C/W
Junction and Storage Temperature Range
-55 to 150
C
Thermal Characteristics
Maximum Junction-to-Lead
C
Steady-State
C/W
Parameter
Units
Maximum Junction-to-Ambient
A
t 10s
R
JA
C/W
Maximum Junction-to-Ambient
A
AO4844
Dual N-Channel Enhancement Mode Field Effect Transistor
Features
V
DS
(V) = 30V
I
D
= 6.9A (V
GS
= 10V)
R
DS(ON)
< 28m
(V
GS
= 10V)
R
DS(ON)
< 42m
(V
GS
= 4.5V)
General Description
The AO4844 uses advanced trench technology to
provide excellent R
DS(ON)
and low gate charge. The
two MOSFETs make a compact and efficient switch
and synchronous rectifier combination for use in buck
converters.
AO4844 is Pb-free (meets ROHS & Sony
259 specifications). AO4844L is a Green Product
ordering option. AO4844 and AO4844L are
electrically identical.
G1
S1
G2
S2
D1
D1
D2
D2
1
2
3
4
8
7
6
5
G1
D1
S1
G2
D2
S2
SOIC-8
Alpha & Omega Semiconductor, Ltd.
AO4844
Symbol
Min
Typ
Max
Units
BV
DSS
30
35
V
0.004
1
T
J
=55C
5
I
GSS
100
nA
V
GS(th)
1
1.72
3
V
I
D(ON)
20
A
22
28
T
J
=125C
31.3
38
32
42
m
g
FS
10
15.4
S
V
SD
0.74
1
V
I
S
3
A
C
iss
680
820
pF
C
oss
102
pF
C
rss
77
pF
R
g
3
4.5
Q
g
(10V)
13.84
17
nC
Q
g
(4.5V)
6.74
8.1
nC
Q
gs
1.82
nC
Q
gd
3.2
nC
t
D(on)
4.6
7
ns
t
r
4.1
6.2
ns
t
D(off)
20.6
30
ns
t
f
5.2
7.5
ns
t
rr
16.5
20
ns
Q
rr
7.8
10
nC
THIS PRODUCT HAS BEEN DESIGNED AND QUALIFIED FOR THE CONSUMER MARKET. APPLICATIONS OR USES AS CRITICAL
COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEMS ARE NOT AUTHORIZED. AOS DOES NOT ASSUME ANY LIABILITY ARISING
OUT OF SUCH APPLICATIONS OR USES OF ITS PRODUCTS. AOS RESERVES THE RIGHT TO IMPROVE PRODUCT DESIGN,
FUNCTIONS AND RELIABILITY WITHOUT NOTICE.
I
F
=6.9A, dI/dt=100A/
s
I
F
=6.9A, dI/dt=100A/
s
Electrical Characteristics (T
J
=25C unless otherwise noted)
Parameter
Conditions
STATIC PARAMETERS
Drain-Source Breakdown Voltage
I
D
=250
A, V
GS
=0V
I
DSS
Zero Gate Voltage Drain Current
V
DS
=24V, V
GS
=0V
A
Gate-Body leakage current
V
DS
=0V, V
GS
=20V
Gate Threshold Voltage
V
DS
=V
GS
I
D
=250
A
On state drain current
V
GS
=4.5V, V
DS
=5V
R
DS(ON)
Static Drain-Source On-Resistance
V
GS
=10V, I
D
=6.9A
m
V
GS
=4.5V, I
D
=5.0A
V
GS
=0V, V
DS
=0V, f=1MHz
Forward Transconductance
V
DS
=5V, I
D
=6.9A
Diode Forward Voltage
I
S
=1A
Maximum Body-Diode Continuous Current
DYNAMIC PARAMETERS
Input Capacitance
V
GS
=0V, V
DS
=15V, f=1MHz
Output Capacitance
Gate Drain Charge
Reverse Transfer Capacitance
Turn-On Rise Time
Turn-Off DelayTime
Gate resistance
Body Diode Reverse Recovery Time
Body Diode Reverse Recovery Charge
Turn-Off Fall Time
SWITCHING PARAMETERS
Total Gate Charge
Total Gate Charge
Gate Source Charge
Turn-On DelayTime
V
GS
=10V, V
DS
=15V, R
L
=2.2
,
R
GEN
=3
V
GS
=10V, V
DS
=15V, I
D
=6.9A
A: The value of R
JA
is measured with the device mounted on 1in
2
FR-4 board with 2oz. Copper, in a still air environment with T
A
=25C. The
value in any given application depends on the user's specific board design. The current rating is based on the t 10s thermal resistance
rating.
B: Repetitive rating, pulse width limited by junction temperature.
C. The R
JA
is the sum of the thermal impedence from junction to lead R
JL
and lead to ambient.
D. The static characteristics in Figures 1 to 6 are obtained using 80
s pulses, duty cycle 0.5% max.
E. These tests are performed with the device mounted on 1 in
2
FR-4 board with 2oz. Copper, in a still air environment with T
A
=25C. The SOA
curve provides a single pulse rating.
Rev 0: Apr. 2006
Alpha & Omega Semiconductor, Ltd.
AO4844
TYPICAL ELECTRICAL AND THERMAL CHARACTERISTICS
0
5
10
15
20
25
30
0
1
2
3
4
5
V
DS
(Volts)
Fig 1: On-Region Characteristics
I
D
(A
)
V
GS
=3V
3.5V
4V
4.5V
10V
0
4
8
12
16
20
0
0.5
1
1.5
2
2.5
3
3.5
4
4.5
V
GS
(Volts)
Figure 2: Transfer Characteristics
I
D
(A
)
10
20
30
40
50
60
0
5
10
15
20
I
D
(Amps)
Figure 3: On-Resistance vs. Drain Current and
Gate Voltage
R
DS
(
O
N)
(m
)
1.0E-05
1.0E-04
1.0E-03
1.0E-02
1.0E-01
1.0E+00
1.0E+01
0.0
0.2
0.4
0.6
0.8
1.0
V
SD
(Volts)
Figure 6: Body diode characteristics
I
S
Am
ps
125C
0.8
0.9
1
1.1
1.2
1.3
1.4
1.5
1.6
0
50
100
150
200
Temperature ( C)
Figure 4: On-Resistance vs. Junction Temperature
Norm
a
lize
d O
n
-
R
e
s
i
s
t
a
n
c
e
V
GS
=10V
V
GS
=4.5V
10
20
30
40
50
60
70
2
4
6
8
10
V
GS
(Volts)
Figure 5: On-Resistance vs. Gate-Source Voltage
R
DS
(
O
N)
(m
)
25C
125C
V
DS
=5V
V
GS
=4.5V
V
GS
=10V
I
D
=6.9A
125C
25C
25C
I
D
=6.9A
5V
6V
Alpha & Omega Semiconductor, Ltd.
AO4844
TYPICAL ELECTRICAL AND THERMAL CHARACTERISTICS
0
2
4
6
8
10
0
2
4
6
8
10
12
14
Q
g
(nC)
Figure 7: Gate-Charge characteristics
V
GS
(V
ol
ts
)
0
100
200
300
400
500
600
700
800
900
1000
0
5
10
15
20
25
30
V
DS
(Volts)
Figure 8: Capacitance Characteristics
C
a
p
acit
a
n
ce (
p
F
)
C
iss
0
10
20
30
40
0.0001
0.01
1
100
10000
Pulse Width (s)
Figure 10: Single Pulse Power Rating Junction-to-
Ambient (Note E)
Po
wer W
0.01
0.1
1
10
0.00001
0.0001
0.001
0.01
0.1
1
10
100
1000
Pulse Width (s)
Figure 11: Normalized Maximum Transient Thermal Impedance
Z
JA
N
o
rmaliz
ed
T
r
an
sien
t
T
h
e
rmal R
esist
an
ce
C
oss
C
rss
0.1
1
10
100
0.1
1
10
100
V
DS
(Volts)
I
D
(Am
p
s
)
Figure 9: Maximum Forward Biased Safe
Operating Area (Note E)
100
s
10ms
1ms
0.1s
1s
10s
DC
R
DS(ON)
limited
T
J(Max)
=150C
T
A
=25C
V
DS
=15V
I
D
=6.9A
Single Pulse
D=T
on
/T
T
J,PK
=T
A
+P
DM
.Z
JA
.R
JA
R
JA
=62.5C/W
T
on
T
P
D
In descending order
D=0.5, 0.3, 0.1, 0.05, 0.02, 0.01, single pulse
T
J(Max)
=150C
T
A
=25C
f=1MHz
V
GS
=0V
10
s
Alpha & Omega Semiconductor, Ltd.
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