DATA SHEET
Product Specification
Supersedes data of October 1992
1996 Oct 21
DISCRETE SEMICONDUCTORS
BLF278
VHF push-pull power MOS
transistor
1996 Oct 21
2
Philips Semiconductors
Product Specification
VHF push-pull power MOS transistor
BLF278
FEATURES
High power gain
Easy power control
Good thermal stability
Gold metallization ensures excellent reliability.
APPLICATIONS
Broadcast transmitters in the VHF frequency range.
DESCRIPTION
Dual push-pull silicon N-channel enhancement mode
vertical D-MOS transistor encapsulated in a 4-lead,
SOT262A1 balanced flange package with two ceramic
caps. The mounting flange provides the common source
connection for the transistors.
CAUTION
The device is supplied in an antistatic package.
The gate-source input must be protected against static
discharge during transport or handling.
PINNING - SOT262A1
PIN
SYMBOL
DESCRIPTION
1
d
1
drain 1
2
d
2
drain 2
3
g
1
gate 1
4
g
2
gate 2
5
s
source
Fig.1 Simplified outline and symbol.
1
2
3
4
MAM098
Top view
5
5
d
g
s
d
g
QUICK REFERENCE DATA
RF performance at T
h
= 25
C in a push-pull common source test circuit.
MODE OF OPERATION
f
(MHz)
V
DS
(V)
P
L
(W)
G
p
(dB)
D
(%)
CW, class-B
108
50
300
>20
>60
CW, class-C
108
50
300
typ. 18
typ. 80
CW, class-AB
225
50
250
>14
typ. 16
>50
typ. 55
WARNING
Product and environmental safety - toxic materials
This product contains beryllium oxide. The product is entirely safe provided that the BeO discs are not damaged.
All persons who handle, use or dispose of this product should be aware of its nature and of the necessary safety
precautions. After use, dispose of as chemical or special waste according to the regulations applying at the location of
the user. It must never be thrown out with the general or domestic waste.
1996 Oct 21
3
Philips Semiconductors
Product Specification
VHF push-pull power MOS transistor
BLF278
LIMITING VALUES
In accordance with the Absolute Maximum System (IEC 134).
THERMAL CHARACTERISTICS
SYMBOL
PARAMETER
CONDITIONS
MIN.
MAX.
UNIT
Per transistor section
V
DS
drain-source voltage
-
110
V
V
GS
gate-source voltage
-
20
V
I
D
drain current (DC)
-
18
A
P
tot
total power dissipation
up to T
mb
= 25
C total device;
both sections equally loaded
-
500
W
T
stg
storage temperature
-
65
150
C
T
j
junction temperature
-
200
C
SYMBOL
PARAMETER
CONDITIONS
VALUE
UNIT
R
th j-mb
thermal resistance from junction
to mounting base
total device; both sections
equally loaded.
max. 0.35
K/W
R
th mb-h
thermal resistance from
mounting base to heatsink
total device; both sections
equally loaded.
max. 0.15
K/W
Fig.2 DC SOAR.
Total device; both sections equally loaded.
(1) Current is this area may be limited by R
DSon
.
(2) T
mb
= 25
C.
handbook, halfpage
1
10
100
1
10
100
(1)
500
I
D
(A)
V (V)
DS
MRA988
(2)
Fig.3 Power derating curves.
Total device; both sections equally loaded.
(1) Continuous operation.
(2) Short-time operation during mismatch.
handbook, halfpage
0
40
80
160
500
0
400
MGE616
120
300
200
100
Ptot
(W)
Th (
C)
(2)
(1)
1996 Oct 21
4
Philips Semiconductors
Product Specification
VHF push-pull power MOS transistor
BLF278
CHARACTERISTICS
T
j
= 25
C unless otherwise specified.
SYMBOL
PARAMETER
CONDITIONS
MIN.
TYP.
MAX.
UNIT
Per transistor section
V
(BR)DSS
drain-source breakdown voltage V
GS
= 0; I
D
= 50 mA
110
-
-
V
I
DSS
drain-source leakage current
V
GS
= 0; V
DS
= 50 V
-
-
2.5
mA
I
GSS
gate-source leakage current
V
GS
=
20 V; V
DS
= 0
-
-
1
A
V
GSth
gate-source threshold voltage
V
DS
= 10 V; I
D
= 50 mA
2
-
4.5
V
V
GS
gate-source voltage difference
of both sections
V
DS
= 10 V; I
D
= 50 mA
-
-
100
mV
g
fs
forward transconductance
V
DS
= 10 V; I
D
= 5 A
4.5
6.2
-
S
g
fs1
/g
fs2
forward transconductance ratio
of both sections
V
DS
= 10 V; I
D
= 5 A
0.9
-
1.1
R
DSon
drain-source on-state resistance V
GS
= 10 V; I
D
= 5 A
-
0.2
0.3
I
DSX
drain cut-off current
V
GS
= 10 V; V
DS
= 10 V
-
25
-
A
C
is
input capacitance
V
GS
= 0; V
DS
= 50 V; f = 1 MHz
-
480
-
pF
C
os
output capacitance
V
GS
= 0; V
DS
= 50 V; f = 1 MHz
-
190
-
pF
C
rs
feedback capacitance
V
GS
= 0; V
DS
= 50 V; f = 1 MHz
-
14
-
pF
C
d-f
drain-flange capacitance
-
5.4
-
pF
Fig.4
Temperature coefficient of gate-source
voltage as a function of drain current; typical
values per section.
V
DS
= 10 V.
handbook, halfpage
0
-
5
10
-
2
10
-
1
MGE623
1
10
-
4
-
3
-
2
-
1
T.C.
(mV/K)
ID (A)
Fig.5
Drain current as a function of gate-source
voltage; typical values per section.
V
DS
= 10 V; T
j
= 25
C.
handbook, halfpage
0
30
20
10
0
5
ID
(A)
10
VGS (V)
15
MGE622
1996 Oct 21
5
Philips Semiconductors
Product Specification
VHF push-pull power MOS transistor
BLF278
Fig.6
Drain-source on-state resistance as a
function of junction temperature; typical
values per section.
V
GS
= 10 V; I
D
= 5 A.
handbook, halfpage
0
50
100
150
400
0
200
100
300
MGE621
RDSon
(m
)
Tj (
C)
Fig.7
Input and output capacitance as functions
of drain-source voltage; typical values per
section.
V
GS
= 0; f = 1 MHz.
handbook, halfpage
0
1200
800
400
0
20
C
(pF)
40
VDS (V)
60
MGE615
Cos
Cis
Fig.8
Feedback capacitance as a function of
drain-source voltage; typical values per
section.
V
GS
= 0; f = 1 MHz.
handbook, halfpage
0
10
50
400
300
100
0
200
MGE620
20
30
40
Crs
(pF)
VDS (V)
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