ARF475FL Datasheet, PDF (4/4 Pages) Advanced Power Technology – RF POWER MOSFET N-CHANNEL ENHANCEMENT MODE

ARF475FL
128MHz Test amplifier
Po = 900W @150V
3ms pulse 10% Duty Cycle
C6
R1
Vg1
R3
L2
TL3
+
+ L3
Vdd
C5
C11
C10 -
J1
C1
T2
T1
C7 ^TL1
C2
C8 _TL2
R2
R4
C1 25pF poly trimmer
C9
C2 750pF ATC 700B
Vg2
C3-4 2200pF NPO 500V chip
C5-10 10nF 500V chip
C11 1000uF 250V electroytic
L1 30nH 1.5t #18 enam .375" dia
L2 680nH 12t #24 enam .312" dia
L3 2t #20 on Fair-Rite 2643006302 bead, ~ 2uH
C3 ^TL5
T3
L1
J2
C4
TL4
TL6
DUT
R1-2 3.1Ω : 3 parallel 22Ω 1W 2512 SMT
R3-4 2.2kΩ 1/4W axial
T1 1:1 balun 50Ω coax on Fair-Rite 2843000102 core
T2 4:1 25Ω coax on 2843000102 Fair-Rite balun core
T3 1:1 coax balun RG-303 on 2861006802 Fair-Rite core
TL1-2 Printed line L= 0.75" w =.23"
TL3-6 Printed line L= 0.65" w =.23"
0.23" wide stripline on FR-4 board is ~ 30Ω Zo
Peak Output Power vs. Vdd and Duty Cycle
900
1.2
800
Max
1
700
Duty Cycle
600
0.8
500
400
Po Watts
0.6
300
0.4
200
0.2
100
0
80
0
100 120 140 160
Drain Supply Voltage Vdd
Thermal Considerations and Package Mounting:
The rated power dissipation is only available when the package
mounting surface is at 25°C and the junction temperature is 175°C .
The thermal resistance between junctions and case mounting sur-
face is 0.3°C/W. When installed, an additional thermal impedance
of 0.1°C/W between the package base and the mounting surface is
typical. Insure that the mounting surface is smooth and flat. Ther-
mal joint compound must be used to reduce the effects of small sur-
face irregularities. Use the minimum amount necessary to coat the
surface. The heatsink should incorporate a copper heat spreader to
obtain best results.
The package design clamps the ceramic base to the heatsink. A
clamped joint maintains the required mounting pressure while al-
lowing for thermal expansion of both the base and the heat sink.
Four 4-40 (M3) screws provide the required mounting force. T = 6
in-lb (0.68N-m).
Notes:
The value of L1 must be adjusted as the supply voltage is
changed to maintain resonance in the output circuit. At
128MHz its value changes from approximately 40nH at
100V to 30nH at 150V.
With the 50Ω drain-to-drain load, the duty cycle above
100V must be reduced to insure power dissipation is
within the limits of the device. Maximum pulse length
should be 100mS or less. See transient thermal
impedance, figure 5.
.050
.050
.125R
S
D1
4 pls
D2
S
.325
.125dia
4 pls
ARF475
.570
.320
S
G1
.225
G2
S
.225
1.500
1.250
.200
.300
.005 .040
HAZARDOUS MATERIAL WARNING
The white ceramic portion of the device between leads and mounting surface is beryllium oxide, BeO. Beryllium oxide dust is toxic when inhaled. Care must be taken during
handling and mounting to avoid damage to this area. These devices must never be thrown away with general industrial or domestic waste.
APT’s products are covered by one or more of U.S.patents 4,895,810 5,045,903 5,089,434 5,182,234 5,019,522
5,262,336 6,503,786 5,256,583 4,748,103 5,283,202 5,231,474 5,434,095 5,528,058 6,939,743 and foreign patents. US and Foreign patents pending. All Rights Reserved.