SCHOTTKY RECTIFIER
30 Amp
21FQ... SERIES
PD-2.043 rev. D 12/97
1
www.irf.com
Dimensions in millimeters and inches
Conforms to JEDEC Outline DO-203AA (DO-4)
CASE STYLE AND DIMENSIONS
The 21FQ Schottky rectifier series has been optimized for
very low forward voltage drop, with moderate leakage. The
proprietary barrier technology allows for reliable operation up
to 150 C junction temperature. Typical applications are in
switching power supplies, converters, free-wheeling diodes,
and reverse battery protection.
150 C T
J
operation
Very low forward voltage drop
High frequency operation
Guard ring for enhanced ruggedness and long term
reliability
Hermetic packaging
I
F(AV)
Rectangular
30
A
waveform
V
RRM
range
35 to 45
V
I
FSM
@ tp = 5 s sine
7800
A
V
F
@
30 Apk, T
J
= 125C
0.51
V
T
J
range
- 65 to 150
C
Characteristics
21FQ...
Units
Major Ratings and Characteristics
Description/Features
21FQ... Series
2
PD-2.043 rev. D 12/97
www.irf.com
V
FM
Max. Forward Voltage Drop (1)
0.57
V
@ 30A
* See Fig. 1
0.69
V
@ 60A
0.51
V
@ 30A
0.65
V
@ 60A
I
RM
Max. Reverse Leakage Current (1)
4
mA
T
J
= 25 C
* See Fig. 2
150
mA
T
J
= 125 C
C
T
Max. Junction Capacitance
1850
pF
V
R
= 5V
DC
, (test signal range 100Khz to 1Mhz) 25 C
L
S
Typical Series Inductance
6.5
nH
Measured from top of terminal to mounting plane
dv/dt Max. Voltage Rate of Change
10,000
V/ s
(Rated V
R
)
T
J
= 25 C
T
J
= 125 C
V
R
= rated V
R
Electrical Specifications
Parameters
21FQ
Units
Conditions
(1) Pulse Width < 300s, Duty Cycle < 2%
T
J
Max. Junction Temperature Range
-65 to 150
C
T
stg
Max. Storage Temperature Range
-65 to 150
C
R
thJC
Max. Thermal Resistance Junction
1.25
C/W
DC operation * See Fig. 4
to Case
R
thCS
Typical Thermal Resistance, Case to
0.50
C/W
Mounting surface , smooth and greased
Heatsink
wt
Approximate Weight
5.8 (0.2)
g (oz.)
T
Mounting Torque
Min.
14 (12)
Non-lubricated threads
Max.
23 (20)
Case Style
DO-203AA(DO-4)
JEDEC
Kg-cm
(Ibf-in)
Thermal-Mechanical Specifications
Parameters
21FQ
Units
Conditions
I
F(AV)
Max. Average Forward Current
30
A
50% duty cycle @ T
C
= 107 C, rectangular wave form
* See Fig. 5
I
FSM
Max. Peak One Cycle Non-Repetitive
7800
5s Sine or 3s Rect. pulse
Surge Current * See Fig. 7
600
10ms Sine or 6ms Rect. pulse
E
AS
Non-Repetitive Avalanche Energy
40
mJ
T
J
= 25 C, I
AS
= 6 Amps, L = 2.2 mH
I
AR
Repetitive Avalanche Current
6
A
Current decaying linearly to zero in 1 sec
Frequency limited by T
J
max. V
A
= 1.5 x V
R
typical
Parameters
21FQ Units
Conditions
A
Absolute Maximum Ratings
Following any rated
load condition and
with rated V
RRM
applied
Part number
21FQ035
21FQ040
21FQ045
V
R
Max. DC Reverse Voltage (V)
V
RWM
Max. Working Peak Reverse Voltage (V)
35
40
45
Voltage Ratings
21FQ... Series
3
PD-2.043 rev. D 12/97
www.irf.com
Fig. 2 - Typical Values of Reverse Current
Vs. Reverse Voltage
Fig. 3 - Typical Junction Capacitance
Vs. Reverse Voltage
Fig. 4 - Maximum Thermal Impedance Z
thJC
Characteristics
.001
.01
.1
1
10
100
1000
0
5
10 15 20 25 30 35 40 45
R
R
125C
100C
75C
50C
25C
Reverse Voltage - V (V)
R
e
v
e
rs
e
C
u
rre
n
t
-
I
(
m
A)
T = 150C
J
.001
.01
.1
1
10
.00001
.0001
.001
.01
.1
1
10
100
D = 0.33
D = 0.50
D = 0.25
D = 0.17
D = 0.08
1
th
J
C
t , Rectangular Pulse Duration (Seconds)
T
h
er
m
a
l
I
m
ped
an
c
e
-
Z
(
C
/W
)
Single Pulse
(Thermal Resistance)
2
t
1
t
P
DM
Notes:
1. Duty factor D = t / t
2. Peak T = P x Z + T
1
J
DM
thJC
C
2
Fig. 1 - Maximum Forward Voltage Drop Characteristics
100
1000
10000
0
10
20
30
40
50
T = 25C
J
Reverse Voltage - V (V)
R
T
J
u
nc
t
i
o
n
C
a
pac
i
t
a
n
c
e
-
C
(
p
F
)
.1
1
10
100
1000
0
.1 .2
.3
.4
.5
.6 .7 .8 .9
1 1.1 1.2
FM
F
I
n
s
t
a
n
t
a
ne
ou
s
F
o
r
w
a
r
d C
ur
r
e
nt
-
I
(
A
)
Forward Voltage Drop - V (V)
T = 150C
T = 125C
T = 25C
J
J
J
21FQ... Series
4
PD-2.043 rev. D 12/97
www.irf.com
Fig. 8 - Unclamped Inductive Test Circuit
Fig. 5 - Maximum Allowable Case Temperature
Vs. Average Forward Current
Fig. 6 - Forward Power Loss Characteristics
Fig. 7 - Maximum Non-Repetitive Surge Current
115
125
135
145
155
0
5
10 15 20 25 30 35 40 45
DC
A
l
l
o
w
a
bl
e C
a
s
e
T
e
m
p
er
at
ur
e -
(
C
)
Average Forward Current - I (A)
F(AV)
21FQ
R (DC) = 1.25C/W
thJC
0
5
10
15
20
25
0
5
10 15 20 25 30 35 40 45
DC
A
v
er
ag
e P
o
w
e
r
Lo
s
s
-
(
W
a
tts
)
F(AV)
D = 0.08
D = 0.17
D = 0.25
D = 0.33
D = 0.50
RMS Limit
Average Forward Current - I (A)
100
1000
10000
10
100
1000
10000
FS
M
p
N
on-
R
epet
i
t
i
v
e S
u
r
ge C
u
r
r
ent
-
I
(
A
)
At Any Rated Load Condition
And With Rated V Applied
Following Surge
RRM
Square Wave Pulse Duration - t (microsec)
FREE-WHEEL
DIODE
40HFL40S02
CURRENT
MONITOR
HIGH-SPEED
SWITCH
IRFP460
L
DUT
Rg = 25 ohm
Vd = 25 Volt
+
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