Datasheet

IRF6644PbF
www.irf.com 3
Fig 3. Maximum Effective Transient Thermal Impedance, Junction-to-Ambient 
1E-006 1E-005 0.0001 0.001 0.01 0.1 1 10 100
t
1
, Rectangular Pulse Duration (sec)
0.0001
0.001
0.01
0.1
1
10
100
T
h
e
r
m
a
l
R
e
s
p
o
n
s
e
(
Z
t
h
J
A
)
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 Zthja + Tc
τ
J
τ
J
τ
1
τ
1
τ
2
τ
2
τ
3
τ
3
R
1
R
1
R
2
R
2
R
3
R
3
Ci i/Ri
Ci= τi/Ri
τ
τ
C
τ
4
τ
4
R
4
R
4
Ri (°C/W) τi (sec)
0.6784 0.00086
17.299 0.57756
17.566 8.94
9.4701 106
Absolute Maximum Ratin
g
s
Parameter Units
P
D
@T
A
= 25°C
Power Dissipation
W
P
D
@T
A
= 70°C
Power Dissipation
P
D
@T
C
= 25°C
Power Dissipation
T
P
Peak Soldering Temperature °C
T
J
Operating Junction and
T
STG
Storage Temperature Range
Thermal Resistance
Parameter Typ. Max. Units
R
θJA
Junction-to-Ambient ––– 45
R
θJA
Junction-to-Ambient 12.5 –––
R
θJA
Junction-to-Ambient 20 ––– °C/W
R
θJC
Junction-to-Case ––– 1.4
R
θJ-PCB
Junction-to-PCB Mounted 1.0 –––
270
-40 to + 150
Max.
89
2.8
1.8
 Surface mounted on 1 in. square Cu board, steady state.
 T
C
measured with thermocouple incontact with top (Drain) of part.
 Used double sided cooling, mounting pad with large heatsink.
Notes:
 Mounted on minimum footprint full size board with metalized
back and with small clip heatsink.
 R
θ
is measured at T
J
of approximately 90°C.
 Surface mounted on 1 in. square Cu
board (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)