1
The RF MOSFET Line
RF Power Field-Effect Transistor
NChannel EnhancementMode MOSFET
Designed for broadband commercial and military applications at frequencies
to 175 MHz. The high power, high gain and broadband performance of this
device makes possible solid state transmitters for FM broadcast or TV channel
frequency bands.
Guaranteed Performance at 175 MHz, 50 V:
Output Power -- 300 W
Gain -- 14 dB (16 dB Typ)
Efficiency -- 50%
Low Thermal Resistance -- 0.35
C/W
Ruggedness Tested at Rated Output Power
Nitride Passivated Die for Enhanced Reliability
MAXIMUM RATINGS
Rating
Symbol
Value
Unit
DrainSource Voltage
V
DSS
125
Vdc
DrainGate Voltage
V
DGO
125
Vdc
GateSource Voltage
V
GS
40
Vdc
Drain Current -- Continuous
I
D
40
Adc
Total Device Dissipation @ T
C
= 25
C
Derate above 25
C
P
D
500
2.85
Watts
W/
C
Storage Temperature Range
T
stg
65 to +150
C
Operating Junction Temperature
T
J
200
C
THERMAL CHARACTERISTICS
Characteristic
Symbol
Max
Unit
Thermal Resistance, Junction to Case
R
JC
0.35
C/W
NOTE -- CAUTION -- MOS devices are susceptible to damage from electrostatic charge. Reasonable precautions in handling and
packaging MOS devices should be observed.
Order this document
by MRF151G/D
SEMICONDUCTOR TECHNICAL DATA
MRF151G
300 W, 50 V, 175 MHz
NCHANNEL
BROADBAND
RF POWER MOSFET
CASE 37504, STYLE 2
D
G
S
(FLANGE)
D
G
REV 9
ELECTRICAL CHARACTERISTICS
(T
C
= 25
C unless otherwise noted.)
Characteristic
Symbol
Min
Typ
Max
Unit
OFF CHARACTERISTICS (Each Side)
DrainSource Breakdown Voltage (V
GS
= 0, I
D
= 100 mA)
V
(BR)DSS
125
--
--
Vdc
Zero Gate Voltage Drain Current (V
DS
= 50 V, V
GS
= 0)
I
DSS
--
--
5.0
mAdc
GateBody Leakage Current (V
GS
= 20 V, V
DS
= 0)
I
GSS
--
--
1.0
Adc
ON CHARACTERISTICS (Each Side)
Gate Threshold Voltage (V
DS
= 10 V, I
D
= 100 mA)
V
GS(th)
1.0
3.0
5.0
Vdc
DrainSource OnVoltage (V
GS
= 10 V, I
D
= 10 A)
V
DS(on)
1.0
3.0
5.0
Vdc
Forward Transconductance (V
DS
= 10 V, I
D
= 5.0 A)
g
fs
5.0
7.0
--
mhos
DYNAMIC CHARACTERISTICS (Each Side)
Input Capacitance (V
DS
= 50 V, V
GS
= 0, f = 1.0 MHz)
C
iss
--
350
--
pF
Output Capacitance (V
DS
= 50 V, V
GS
= 0, f = 1.0 MHz)
C
oss
--
220
--
pF
Reverse Transfer Capacitance (V
DS
= 50 V, V
GS
= 0, f = 1.0 MHz)
C
rss
--
15
--
pF
FUNCTIONAL TESTS
Common Source Amplifier Power Gain
(V
DD
= 50 V, P
out
= 300 W, I
DQ
= 500 mA, f = 175 MHz)
G
ps
14
16
--
dB
Drain Efficiency
(V
DD
= 50 V, P
out
= 300 W, f = 175 MHz, I
D
(Max) = 11 A)
50
55
--
%
Load Mismatch
(V
DD
= 50 V, P
out
= 300 W, I
DQ
= 500 mA,
VSWR 5:1 at all Phase Angles)
No Degradation in Output Power
Figure 1. 175 MHz Test Circuit
+
R1
C5
C4
C10
C9
BIAS 0 6 V
INPUT
D.U.T.
OUTPUT
+
T2
L1
C11
C1
T1
C12
50 V
L2
C1
R2
C2
C3
C6
C7
C8
R1 -- 100 Ohms, 1/2 W
R2 -- 1.0 kOhm, 1/2 W
C1 -- Arco 424
C2 -- Arco 404
C3, C4, C7, C8, C9 -- 1000 pF Chip
C5, C10 -- 0.1
F Chip
C6 -- 330 pF Chip
C11 -- 0.47
F Ceramic Chip, Kemet 1215 or
C11 --
Equivalent (100 V)
C12 -- Arco 422
L1 -- 10 Turns AWG #18 Enameled Wire,
L1 --
Close Wound, 1/4
I.D.
L2 -- Ferrite Beads of Suitable Material for
L2 --
1.5 2.0
H Total Inductance
Unless Otherwise Noted, All Chip Capacitors are ATC Type 100 or
Equivalent.
T1 -- 9:1 RF Transformer. Can be made of 15 18 Ohms
T1 --
Semirigid CoAx, 62 90 Mils O.D.
T2 -- 1:4 RF Transformer. Can be made of 16 18 Ohms
T2 --
Semirigid CoAx, 7090 Mils O.D.
Board Material -- 0.062
Fiberglass (G10),
1 oz. Copper Clad, 2 Sides,
r
= 5.0
NOTE: For stability, the input transformer T1 must be loaded
NOTE:
with ferrite toroids or beads to increase the common
NOTE:
mode inductance. For operation below 100 MHz. The
NOTE:
same is required for the output transformer.
See Figure 6 for construction details of T1 and T2.
2
REV 9
Figure 2. Capacitance versus
DrainSource Voltage*
Figure 3. Common Source Unity Gain Frequency
versus Drain Current*
Figure 4. GateSource Voltage versus
Case Temperature*
Figure 5. DC Safe Operating Area
TYPICAL CHARACTERISTICS
Figure 6. RF Transformer
*Data shown applies to each half of MRF151G.
V
GS
, DRAIN-SOURCE VOL
T
AGE
(NORMALIZED)
1000
500
200
100
50
0
20
0
10
20
30
40
50
C, CAP
ACIT
ANCE
(pF)
V
DS
, DRAINSOURCE VOLTAGE (VOLTS)
1.04
0.9
25
0
25
50
75
100
T
C
, CASE TEMPERATURE (
C)
1.03
1.02
1.01
1
0.99
0.98
0.97
0.96
0.95
0.94
0.93
0.92
0.91
C
iss
C
oss
C
rss
I
D
= 5 A
4 A
2 A
1 A
250 mA
100 mA
100
10
1
2
20
200
V
DS
, DRAINTOSOURCE VOLTAGE (VOLTS)
2000
0
0
4
8
12
16
20
I
D
, DRAIN CURRENT (AMPS)
1000
V
DS
= 30 V
I D
, DRAIN CURRENT
(AMPS)
2
6
10
14
18
15 V
T
C
= 25
C
f T
, UNITY
GAIN FREQUENCY
(MHz)
HIGH IMPEDANCE
WINDINGS
CENTER
TAP
CENTER
TAP
4:1
IMPEDANCE
RATIO
9:1
IMPEDANCE
RATIO
CONNECTIONS
TO LOW IMPEDANCE
WINDINGS
3
REV 9
Figure 7. Output Power versus Input Power
Figure 8. Power Gain versus Frequency
TYPICAL CHARACTERISTICS
Figure 9. Input and Output Impedance
30
5
2
5
10
30
100
200
f, FREQUENCY (MHz)
V
DD
= 50 V
I
DQ
= 2 x 250 mA
P
out
= 150 W
25
20
15
10
350
0
0
5
10
P
in
, INPUT POWER (WATTS)
300
250
200
150
100
50
V
DD
= 50 V
I
DQ
= 2 x 250 mA
200 MHz
G
PS
, POWER GAIN (dB)
P out
, OUTPUT
POWER (W
A
TTS)
175 MHz
f = 150 MHz
150
30
f = 175 MHz
Z
o
= 10
Z
OL
* = Conjugate of the optimum load impedance
Z
OL
* =
into which the device output operates at a
Z
OL
* =
given output power, voltage and frequency.
f = 175 MHz
125
100
INPUT, Z
in
(GATE TO GATE)
OUTPUT, Z
OL
*
(DRAIN TO DRAIN)
150
125
100
30
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