Datasheet

www.irf.com 1
08/28/06
DirectFET Power MOSFET 
Description
The IRF6668PbF combines the latest HEXFET® Power MOSFET Silicon technology with the advanced DirectFET
TM
packag-
ing to achieve the lowest on-state resistance in a package that has the footprint of a SO-8 and only 0.7 mm profile. The
DirectFET package is compatible with existing layout geometries used in power applications, PCB assembly equipment and
vapor phase, infra-red or convection soldering techniques. Application note AN-1035 is followed regarding the manufacturing
methods and processes. The DirectFET package allows dual sided cooling to maximize thermal transfer in power systems,
improving previous best thermal resistance by 80%.
The IRF6668PbF is optimized for primary side bridge topologies in isolated DC-DC applications, for 48V(±10%) or 36V-60V
ETSI input voltage range systems. The IRF6668PbF is also ideal for secondary side synchronous rectification in regulated
isolated DC-DC topologies. The reduced total losses in the device coupled with the high level of thermal performance enables
high efficiency and low temperatures, which are key for system reliability improvements, and makes this device ideal for high
performance isolated DC-DC converters.
Applicable DirectFET Outline and Substrate Outline (see p.7,8 for details)
Fig 1. Typical On-Resistance vs. Gate-to-Source Voltage
Typical values (unless otherwise specified)
Fig 2. Total Gate Charge vs. Gate-to-Source Voltage
DirectFET ISOMETRIC
MZ
l RoHs Compliant 
l Lead-Free (Qualified up to 260°C Reflow)
l Application Specific MOSFETs
l Ideal for High Performance Isolated Converter
Primary Switch Socket
l Optimized for Synchronous Rectification
l Low Conduction Losses
l High Cdv/dt Immunity
l Low Profile (<0.7mm)
l Dual Sided Cooling Compatible 
l Compatible with existing Surface Mount Techniques 
IRF6668PbF
IRF6668TRPbF
 Click on this section to link to the appropriate technical paper.
 Click on this section to link to the DirectFET Website.
 Surface mounted on 1 in. square Cu board, steady state.
 T
C
measured with thermocouple mounted to top (Drain) of part.
 Repetitive rating; pulse width limited by max. junction temperature.
 Starting T
J
= 25°C, L = 0.088mH, R
G
= 25Ω, I
AS
= 23A.
Notes:
SQ SX ST MQ MX MT MZ
4 6 8 10 12 14 16
V
GS,
Gate -to -Source Voltage (V)
0
10
20
30
40
50
60
T
y
p
i
c
a
l
R
D
S
(
o
n
)
(
m
Ω
)
I
D
= 12A
T
J
= 25°C
T
J
= 125°C
Absolute Maximum Ratin
g
s
Parameter Units
V
DS
Drain-to-Source Voltage V
V
GS
Gate-to-Source Voltage
I
D
@ T
C
= 25°C
Continuous Drain Current, V
GS
@ 10V
I
D
@ T
C
= 70°C
Continuous Drain Current, V
GS
@ 10V
A
I
DM
Pulsed Drain Current
E
AS
Single Pulse Avalanche Energy mJ
I
AR
Avalanche Current A
44
23
Max.
55
170
±20
80
24
024681012141618202224
Q
G
, Total Gate Charge (nC)
0.0
2.0
4.0
6.0
8.0
10.0
12.0
V
G
S
,
G
a
t
e
-
t
o
-
S
o
u
r
c
e
V
o
l
t
a
g
e
(
V
)
V
DS
= 64V
V
DS
= 40V
I
D
= 12A
V
DSS
V
GS
80V max ±20V max
R
DS(on)
12mΩ@ 10V
Q
g tot
Q
gd
Q
gs2
Q
rr
Q
oss
V
gs(th)
22nC 7.8nC 1.6nC 40nC 12nC 4.0V
PD - 97232A