P0120008P Datasheet, PDF (10/13 Pages) Eudyna Devices Inc – 1W GaAs Power FET (Pb-Free Type)

P0120008P
1W GaAs Power FET (Pb-Free Type)
Technical Note
SUMITOMO ELECTRIC
The junction temperature can be calculated by the following
formula.
T_jmax=(Vds*Ids-P_out)(R_th+R_board+R_hs)+T_a
P_out: Output power
R_th: Thermal resistance between channel and case
R_board: Thermal resistance of PCB
R_hs: Thermal resistance of heat sink
T_a: Ambient temperature
T_jmax: Maximum junction temperature
Generally, there are two ways of heat radiation. One is the
plated thru hole and the other is the heat sink. Key points will
be illustrated in each case below. Note that no measure
against oscillation is adopted in the figures. In the design of
circuit and layout, you should take stabilizing into account if
necessary.
[Using Heat Sink]
If you cannot get the junction temperature lower than the
absolute maximum rating only with the plated thru holes,
then you need to employ the heat sink. Attaching the heat
sink directly under pin 4 of the device improves the thermal
resistance between junction and ambient.
4-R0.3
Heatsink
1.9×2.85
(4-R0.3)
φ 3 Plated Thru Hole
for 2.5 M achine Screws
φ5 Soldermask Keepout
2
φ0.4 Plated Thru Holes
[Using Thru Hole]
□Multiple plated thru holes are required directly below the
device.
□Place more than 2 machine screws as close to the ground
pin (pin 4) as possible. The PCB is screwed on the
mounting plate or the heat sink to lower the thermal
resistance of the PCB.
□Lay out a large ground pad area with multiple plated thru
holes around pin 4 of the device.
□The required matching and feedback circuit described in
the application circuit examples should be connected to
the device, although it is not shown in the figure below.
Package Outline
φ5 Soldermask
Keep out
φ 3 Plated Thru Hole
for 2.5 M achine Screws
φ5 Soldermask Keepout
φ0.3 Plated Thru Holes
φ0.4 Plated Thru Holes
Grand Plane
φ 3 Plated Thru Hole
for 2.5 M achine Screws
Grand Plane
Grand Plane
Package Outline
φ 3 Plated Thru Hole
for 2.5 M achine Screws
φ5 Soldermask Keepout
[Note]
□Ground/thermal vias are critical for the proper device
performance. Drills of the recommended diameters should
be used in the fabrication of vias.
□Add as much copper a s possible to inner and outer layers
near the part to ensure optimal thermal performance.
□Mounting screws can be added near the part to fasten the
board to heat sink. Ensure that the ground/thermal via region
contacts the heat sink.
□Do not put solder mask on the backside of the PCB in the
region where the board contacts the heat sink.
□RF trace width depends upon the PCB material and
construction.
□Use 1 oz. Copper minimum.
Specifications and information are subject to change without notice.
2003-11
Sumitomo Electric Industries, Ltd. 1,Taya-cho, Sakae-ku, Yokohama, 244-8588 Japan
Phone: [phone] Fax: [phone] e-mail : [e-mail] Web Site: www.sei.co.jp/GaAsIC/
-10-