DirectFET
®
Power MOSFET
Fig 1. Typical On-Resistance vs. Gate Voltage
Fig 2. Maximum Drain Current vs. Case Temperature
Benefits
l
Improved Gate, Avalanche and Dynamic dV/dt
Ruggedness
l
Fully Characterized Capacitance and Avalanche
SOA
l
Enhanced body diode dV/dt and dI/dt Capability
l
RoHS Compliant Containing no Lead, no Bromide
and no Halogen
Applications
l
Brushed Motor drive applications
l
BLDC Motor drive applications
l
Battery powered circuits
l
Half-bridge and full-bridge topologies
l
Synchronous rectifier applications
l
Resonant mode power supplies
l
OR-ing and redundant power switches
l
DC/DC and AC/DC converters
l
DC/AC Inverters
DirectFET
ISOMETRIC
MX
25
50
75
100
125
150
TC , Case Temperature (°C)
0
50
100
150
200
I D
,
D
ra
in
C
ur
re
nt
(
A
)
Limited By Package
D
D
G
S
S
V
DSS
40V
R
DS(on)
typ.
1.1mΩ
max.
1.4m
Ω
I
D (Silicon Limited)
198A
c
I
D (Package Limited)
90A
4
6
8
10
12
14
16
18
20
VGS, Gate -to -Source Voltage (V)
0.0
2.0
4.0
6.0
R
D
S
(o
n)
,
D
ra
in
-t
o
-S
ou
rc
e
O
n
R
es
is
ta
nc
e
(m
Ω
)
ID = 90A
TJ = 25°C
TJ = 125°C
Strong
IR
FET
IRF7946PbF
1
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Form
Quantity
IRF7946TRPbF
DirectFET MX
Tape and Reel
4800
IRF7946TRPbF
Complete Part Number
Base part number
Package Type
Standard Pack
2
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IRF7946PbF
Notes:
Mounted on minimum footprint full size board with metalized
back and with small clip heatsink.
Used double sided cooling , mounting pad with large heatsink.
T
C
measured with thermocouple mounted to top (Drain) of part.
Surface mounted on 1 in. square Cu
(still air).
Mounted to a PCB with
small clip heatsink (still air)
Mounted on minimum
footprint full size board with
metalized back and with small
clip heatsink (still air)
Absolute Maximum Ratings
Symbol
Parameter
Units
I
D
@ T
C
= 25°C
Continuous Drain Current, V
GS
@ 10V (Silicon Limited)
I
D
@ T
C
= 100°C
Continuous Drain Current, V
GS
@ 10V (Silicon Limited)
I
DM
Pulsed Drain Current
d
P
D
@T
C
= 25°C
Maximum Power Dissipation
W
Linear Derating Factor
W/°C
V
GS
Gate-to-Source Voltage
V
T
J
Operating Junction and
T
STG
Storage Temperature Range
Avalanche Characteristics
E
AS (Thermally limited)
Single Pulse Avalanche Energy
e
mJ
E
AS (Thermally limited)
Single Pulse Avalanche Energy
l
I
AR
Avalanche Current
d
A
E
AR
Repetitive Avalanche Energy
d
mJ
Thermal Resistance
Symbol
Parameter
Typ.
Max.
Units
R
θJA
Junction-to-Ambient
n
–––
45
R
θJA
Junction-to-Ambient
p
12.5
–––
R
θJA
Junction-to-Ambient
o
20
–––
°C/W
R
θJC
Junction-to-Case
qk
–––
1.3
R
θJA-PCB
Junction-to-PCB Mounted
1.0
–––
96
Max.
198
c
125
c
793
200
-55 to + 150
A
°C
85
See Fig. 14, 15, 22a, 22b
± 20
0.77
Static @ T
J
= 25°C (unless otherwise specified)
Symbol
Parameter
Min.
Typ.
Max.
Units
V
(BR)DSS
Drain-to-Source Breakdown Voltage
40
–––
–––
V
ΔV
(BR)DSS
/
ΔT
J
Breakdown Voltage Temp. Coefficient
–––
0.03
–––
V/°C
R
DS(on)
Static Drain-to-Source On-Resistance
–––
1.1
1.4
m
Ω
1.7
–––
m
Ω
V
GS(th)
Gate Threshold Voltage
2.2
3.0
3.9
V
I
DSS
Drain-to-Source Leakage Current
–––
–––
1.0
μA
–––
–––
150
I
GSS
Gate-to-Source Forward Leakage
–––
–––
100
nA
Gate-to-Source Reverse Leakage
–––
–––
-100
R
G
Internal Gate Resistance
–––
0.67
–––
Ω
V
GS
= 20V
V
GS
= -20V
V
DS
= 40V, V
GS
= 0V
V
DS
= 40V, V
GS
= 0V, T
J
= 125°C
V
GS
= 6.0V, I
D
= 72A
g
Conditions
V
GS
= 0V, I
D
= 250μA
Reference to 25°C, I
D
= 1.0mA
d
V
GS
= 10V, I
D
= 90A
g
V
DS
= V
GS
, I
D
= 150μA
3
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IRF7946PbF
S
D
G
Notes:
Calculated continuous current based on maximum allowable
junction temperature. Package limit is 90A.
Repetitive rating; pulse width limited by max. junction
temperature.
Limited by T
Jmax
, starting T
J
= 25°C, L = 0.021mH
R
G
= 50
Ω, I
AS
= 90A, V
GS
=10V.
I
SD
≤ 90A, di/dt ≤ 1135A/μs, V
DD
≤ V
(BR)DSS
, T
J
≤ 150°C.
Pulse width ≤ 400μs; duty cycle ≤ 2%.
C
oss
eff. (TR) is a fixed capacitance that gives the same charging time
as C
oss
while V
DS
is rising from 0 to 80% V
DSS
.
C
oss
eff. (ER) is a fixed capacitance that gives the same energy as
C
oss
while V
DS
is rising from 0 to 80% V
DSS
.
When mounted on 1" square PCB (FR-4 or G-10 Material). For recom
mended footprint and soldering techniques refer to application note #AN-994.
R
θ
is measured at T
J
approximately 90°C.
Limited by T
Jmax
starting
T
J
= 25°C, L= 1mH, R
G
= 50
Ω, I
AS
= 20A, V
GS
=10V
Dynamic @ T
J
= 25°C (unless otherwise specified)
Symbol
Parameter
Min.
Typ.
Max.
Units
gfs
Forward Transconductance
91
–––
–––
S
Q
g
Total Gate Charge
–––
141
212
nC
Q
gs
Gate-to-Source Charge
–––
36
–––
Q
gd
Gate-to-Drain ("Miller") Charge
–––
44
–––
Q
sync
Total Gate Charge Sync. (Q
g
- Q
gd
)
–––
97
–––
t
d(on)
Turn-On Delay Time
–––
20
–––
ns
t
r
Rise Time
–––
49
–––
t
d(off)
Turn-Off Delay Time
–––
54
–––
t
f
Fall Time
–––
41
–––
C
iss
Input Capacitance
–––
6852
–––
pF
C
oss
Output Capacitance
–––
1046
–––
C
rss
Reverse Transfer Capacitance
–––
735
–––
C
oss
eff. (ER)
Effective Output Capacitance (Energy Related)
–––
1307
–––
C
oss
eff. (TR)
Effective Output Capacitance (Time Related)
–––
1465
–––
Diode Characteristics
Symbol
Parameter
Min.
Typ.
Max.
Units
I
S
Continuous Source Current
–––
–––
96
c
A
(Body Diode)
I
SM
Pulsed Source Current
–––
–––
793
A
(Body Diode)d
V
SD
Diode Forward Voltage
–––
0.75
1.2
V
dv/dt
Peak Diode Recovery f
–––
1.6
–––
V/ns
t
rr
Reverse Recovery Time
–––
49
–––
ns
T
J
= 25°C
V
R
= 34V,
–––
50
–––
T
J
= 125°C
I
F
= 90A
Q
rr
Reverse Recovery Charge
–––
74
–––
nC
T
J
= 25°C
di/dt = 100A/μs g
–––
73
–––
T
J
= 125°C
I
RRM
Reverse Recovery Current
–––
2.6
–––
A
T
J
= 25°C
T
J
= 175°C, I
S
= 90A, V
DS
= 40V
I
D
= 30A
R
G
= 2.7
Ω
V
GS
= 10V g
V
DD
= 20V
T
J
= 25°C, I
S
= 90A, V
GS
= 0V g
integral reverse
p-n junction diode.
MOSFET symbol
showing the
Conditions
Conditions
V
DS
= 10V, I
D
= 90A
V
DS
=20V
ƒ = 1.0 MHz
I
D
= 90A, V
DS
=0V, V
GS
= 10V
V
GS
= 0V, V
DS
= 0V to 32V i
V
GS
= 0V, V
DS
= 0V to 32V h
I
D
= 90A
V
GS
= 10V g
V
GS
= 0V
V
DS
= 25V
4
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IRF7946PbF
Fig 3. Typical Output Characteristics
Fig 5. Typical Transfer Characteristics
Fig 6. Normalized On-Resistance vs. Temperature
Fig 4. Typical Output Characteristics
Fig 8. Typical Gate Charge vs. Gate-to-Source Voltage
Fig 7. Typical Capacitance vs. Drain-to-Source Voltage
0.1
1
10
100
VDS, Drain-to-Source Voltage (V)
1
10
100
1000
I D
, D
ra
in
-t
o-
S
ou
rc
e
C
ur
re
nt
(
A
)
VGS
TOP
15V
10V
8.0V
7.0V
6.0V
5.5V
5.0V
BOTTOM
4.5V
≤60μs PULSE WIDTH
Tj = 25°C
4.5V
0.1
1
10
100
VDS, Drain-to-Source Voltage (V)
10
100
1000
I D
, D
ra
in
-t
o-
S
ou
rc
e
C
ur
re
nt
(
A
)
4.5V
≤60μs PULSE WIDTH
Tj = 150°C
VGS
TOP
15V
10V
8.0V
7.0V
6.0V
5.5V
5.0V
BOTTOM
4.5V
2
3
4
5
6
7
8
VGS, Gate-to-Source Voltage (V)
1.0
10
100
1000
I D
, D
ra
in
-t
o-
S
ou
rc
e
C
ur
re
nt
(
A
)
TJ = 25°C
TJ = 150°C
VDS = 10V
≤60μs PULSE WIDTH
-60 -40 -20 0 20 40 60 80 100 120 140 160
TJ , Junction Temperature (°C)
0.6
0.8
0.8
1.0
1.0
1.2
1.2
1.4
1.4
1.6
1.6
1.8
0.6
0.8
1.0
1.2
1.4
1.6
R
D
S
(o
n)
,
D
ra
in
-t
o-
S
ou
rc
e
O
n
R
es
is
ta
nc
e
(
N
or
m
al
iz
ed
)
ID = 90A
VGS = 10V
1
10
100
VDS, Drain-to-Source Voltage (V)
100
1000
10000
100000
C
, C
ap
ac
ita
nc
e
(p
F
)
VGS = 0V, f = 1 MHZ
Ciss = Cgs + Cgd, C ds SHORTED
Crss = Cgd
Coss = Cds + Cgd
Coss
Crss
Ciss
0
20
40
60
80 100 120 140 160 180
QG, Total Gate Charge (nC)
0.0
2.0
4.0
6.0
8.0
10.0
12.0
14.0
V
G
S
, G
at
e-
to
-S
ou
rc
e
V
ol
ta
ge
(
V
)
VDS= 32V
VDS= 20V
ID= 90A
5
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IRF7946PbF
Fig 10. Maximum Safe Operating Area
Fig 11. Drain-to-Source Breakdown Voltage
Fig 9. Typical Source-Drain Diode
Forward Voltage
Fig 12. Typical C
OSS
Stored Energy
Fig 13. Typical On-Resistance vs. Drain Current
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
VSD, Source-to-Drain Voltage (V)
1.0
10
100
1000
I S
D
, R
ev
er
se
D
ra
in
C
ur
re
nt
(
A
)
TJ = 25°C
TJ = 150°C
VGS = 0V
0.1
1
10
100
VDS, Drain-to-Source Voltage (V)
0.01
0.1
1
10
100
1000
10000
I D
,
D
ra
in
-t
o-
S
ou
rc
e
C
ur
re
nt
(
A
)
Tc = 25°C
Tj = 150°C
Single Pulse
10msec
1msec
OPERATION IN THIS AREA
LIMITED BY R DS(on)
100μsec
DC
Limited by
Package
-60 -40 -20 0 20 40 60 80 100 120 140 160
TJ , Temperature ( °C )
40
41
42
43
44
45
46
47
48
V
(B
R
)D
S
S
, D
ra
in
-t
o-
S
ou
rc
e
B
re
ak
do
w
n
V
ol
ta
ge
(
V
)
Id = 1.0mA
0
5
10
15
20
25
30
35
40
45
VDS, Drain-to-Source Voltage (V)
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
E
ne
rg
y
(μ
J)
VDS= 0V to 32V
0
200
400
600
800
1000
ID, Drain Current (A)
0.0
2.0
4.0
6.0
8.0
10.0
R
D
S
(o
n)
,
D
ra
in
-t
o
-S
ou
rc
e
O
n
R
es
is
ta
nc
e
(m
Ω
)
VGS = 5.5V
VGS = 6.0V
VGS = 7.0V
VGS = 8.0V
VGS =10V
6
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IRF7946PbF
Fig 14. Maximum Effective Transient Thermal Impedance, Junction-to-Case
Fig 15. Typical Avalanche Current vs.Pulsewidth
Fig 16. Maximum Avalanche Energy vs. Temperature
Notes on Repetitive Avalanche Curves , Figures 14, 15:
(For further info, see AN-1005 at www.irf.com)
1. Avalanche failures assumption:
Purely a thermal phenomenon and failure occurs at a temperature far in
excess of T
jmax
. This is validated for every part type.
2. Safe operation in Avalanche is allowed as long asT
jmax
is not exceeded.
3. Equation below based on circuit and waveforms shown in Figures 16a, 16b.
4. P
D (ave)
= Average power dissipation per single avalanche pulse.
5. BV = Rated breakdown voltage (1.3 factor accounts for voltage increase
during avalanche).
6. I
av
= Allowable avalanche current.
7.
ΔT
=
Allowable rise in junction temperature, not to exceed
T
jmax
(assumed as
25°C in Figure 14, 15).
t
av =
Average time in avalanche.
D = Duty cycle in avalanche = t
av
·f
Z
thJC
(D, t
av
) = Transient thermal resistance, see Figures 13)
P
D (ave)
= 1/2 ( 1.3·BV·I
av
) =
DT/ Z
thJC
I
av
=
2
DT/ [1.3·BV·Z
th
]
E
AS (AR)
= P
D (ave)
·t
av
1E-006
1E-005
0.0001
0.001
0.01
0.1
t1 , Rectangular Pulse Duration (sec)
0.001
0.01
0.1
1
10
T
he
rm
al
R
es
po
ns
e
(
Z
th
JC
)
°
C
/W
0.20
0.10
D = 0.50
0.02
0.01
0.05
SINGLE PULSE
( THERMAL RESPONSE )
Notes:
1. Duty Factor D = t1/t2
2. Peak Tj = P dm x Zthjc + Tc
1.0E-06
1.0E-05
1.0E-04
1.0E-03
1.0E-02
1.0E-01
tav (sec)
0.1
1
10
100
1000
A
va
la
nc
he
C
ur
re
nt
(
A
)
Allowed avalanche Current vs avalanche
pulsewidth, tav, assuming
ΔΤ j = 25°C and
Tstart = 125°C.
Allowed avalanche Current vs avalanche
pulsewidth, tav, assuming
ΔTj = 125°C and
Tstart =25°C (Single Pulse)
25
50
75
100
125
150
Starting TJ , Junction Temperature (°C)
0
10
20
30
40
50
60
70
80
90
E
A
R
,
A
va
la
nc
he
E
ne
rg
y
(m
J)
TOP Single Pulse
BOTTOM 1.0% Duty Cycle
ID = 90A
7
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IRF7946PbF
Fig. 18 - Typical Recovery Current vs. di
f
/dt
Fig 17. Threshold Voltage vs. Temperature
Fig. 20 - Typical Stored Charge vs. di
f
/dt
Fig. 19 - Typical Recovery Current vs. di
f
/dt
Fig. 21 - Typical Stored Charge vs. di
f
/dt
-75 -50 -25
0
25
50
75 100 125 150
TJ , Temperature ( °C )
1.0
1.5
2.0
2.5
3.0
3.5
4.0
V
G
S
(t
h)
, G
at
e
th
re
sh
ol
d
V
ol
ta
ge
(
V
)
ID = 150μA
ID = 1.0mA
ID = 1.0A
0
200
400
600
800
1000
diF /dt (A/μs)
0
2
4
6
8
10
12
14
16
I R
R
M
(
A
)
IF = 54A
VR = 34V
TJ = 25°C
TJ = 125°C
0
200
400
600
800
1000
diF /dt (A/μs)
0
2
4
6
8
10
12
14
16
I R
R
M
(
A
)
IF = 90A
VR = 34V
TJ = 25°C
TJ = 125°C
0
200
400
600
800
1000
diF /dt (A/μs)
50
100
150
200
250
300
350
Q
R
R
(
nC
)
IF = 54A
VR = 34V
TJ = 25°C
TJ = 125°C
0
200
400
600
800
1000
diF /dt (A/μs)
50
100
150
200
250
300
350
400
Q
R
R
(
nC
)
IF = 90A
VR = 34V
TJ = 25°C
TJ = 125°C
8
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IRF7946PbF
Fig 23a. Switching Time Test Circuit
Fig 23b. Switching Time Waveforms
Fig 22b. Unclamped Inductive Waveforms
Fig 22a. Unclamped Inductive Test Circuit
tp
V
(BR)DSS
I
AS
RG
IAS
0.01
Ω
tp
D.U.T
L
VDS
+
- VDD
DRIVER
A
15V
20V
V
GS
Fig 24a. Gate Charge Test Circuit
Fig 24b. Gate Charge Waveform
Vds
Vgs
Id
Vgs(th)
Qgs1 Qgs2
Qgd
Qgodr
Fig 22.
Peak Diode Recovery dv/dt Test Circuit for N-Channel
HEXFET
®
Power MOSFETs
Circuit Layout Considerations
• Low Stray Inductance
• Ground Plane
• Low Leakage Inductance
Current Transformer
P.W.
Period
di/dt
Diode Recovery
dv/dt
Ripple
≤ 5%
Body Diode Forward Drop
Re-Applied
Voltage
Reverse
Recovery
Current
Body Diode Forward
Current
V
GS
=10V
V
DD
I
SD
Driver Gate Drive
D.U.T. I
SD
Waveform
D.U.T. V
DS
Waveform
Inductor Curent
D =
P.W.
Period
*
V
GS
= 5V for Logic Level Devices
*
+
-
+
+
+
-
-
-
R
G
V
DD
• dv/dt controlled by R
G
• Driver same type as D.U.T.
• I
SD
controlled by Duty Factor "D"
• D.U.T. - Device Under Test
D.U.T
Inductor Current
D.U.T.
V
DS
I
D
I
G
3mA
V
GS
.3
μF
50K
Ω
.2
μF
12V
Current Regulator
Same Type as D.U.T.
Current Sampling Resistors
+
-
V
DS
90%
10%
V
GS
t
d(on)
t
r
t
d(off)
t
f
V
DS
Pulse Width ≤ 1 µs
Duty Factor ≤ 0.1 %
R
D
V
GS
R
G
D.U.T.
10V
+
-
V
DD
V
GS
9
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IRF7946PbF
DirectFET
®
Board Footprint, MX Outline
(Medium Size Can, X-Designation).
Please see DirectFET application note AN-1035 for all details regarding the assembly of DirectFET.
This includes all recommendations for stencil and substrate designs.
G
S
G=GATE
D=DRAIN
S=SOURCE
S
D
D
D
D
Note: For the most current drawing please refer to IR website at:
http://www.irf.com/package/
10
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2014 International Rectifier
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November 25, 2014
IRF7946PbF
DirectFET
®
Part Marking
DirectFET
®
Outline Dimension, MX Outline
(Medium Size Can, X-Designation).
Please see DirectFET application note AN-1035 for all details regarding the assembly of DirectFET. This includes
all recommendations for stencil and substrate designs.
GATE MARKING
PART NUMBER
LOGO
BATCH NUMBER
DATE CODE
Line above the last character of
the date code indicates "Lead-Free"
CODE
A
B
C
D
E
F
G
H
J
K
L
M
P
0.017
0.028
0.007
0.040
0.095
0.156
0.028
0.018
0.028
MAX
0.250
0.38
0.59
0.08
0.88
2.28
3.85
0.68
0.35
0.68
MIN
6.25
4.80
0.42
0.70
0.17
1.02
2.42
3.95
0.72
0.45
0.72
MAX
6.35
5.05
0.015
0.023
0.003
0.090
0.035
0.152
0.027
0.027
0.014
MIN
0.189
0.246
METRIC
IMPERIAL
DIMENSIONS
1.38
1.42
0.80
0.84
0.056
0.054
0.033
0.031
R
0.03
0.08
0.001
0.003
Dimensions are shown in
millimeters (inches)
0.199
Note: For the most current drawing please refer to IR website at:
http://www.irf.com/package/