SKY65045-70LF Datasheet, PDF (18/22 Pages) Skyworks Solutions Inc. – 390 - 1500 MHz Low Noise Power Amplifier Driver

Data Sheet • SKY65045-70LF
Evaluation Board Description
The Skyworks SKY65045-70LF Evaluation Board is used to test
the performance of the SKY65045-70LF low noise power amplifier
module. The following design considerations are general in nature
and must be followed regardless of final use or configuration.
1. Paths to ground should be made as short as possible.
2. The ground pad of the SKY65045-70LF low noise power
amplifier module has special electrical and thermal grounding
requirements. This pad is the main thermal conduit for heat
dissipation. Since the circuit board acts as the heat sink, it
must shunt as much heat as possible from the amplifiers. As
such, design the connection to the ground pad to dissipate the
maximum wattage produced to the circuit. Multiple vias to the
grounding layer are required.
3. Bypass capacitors should be used on the DC supply lines. RF
inductor is required on the V_cc supply line to block RF signal
from the DC supply. See Evaluation Board schematic drawing
for more details.
4. The RF lines should be well separated from each other, with
solid ground in between traces, to maximize input-to-output
isolation.
NOTE: Junction temperature (T_J) of the device increases with a
poor connection to the slug and ground. This reduces the
lifetime of the device.
Evaluation Board Test Procedure
Use the following procedure to set up the SKY65045-70LF evalu-
ation board for testing.
1. Connect a 5 V supply to V_CC. If available, enable the current
limiting function of the power supply to 100 mA.
2. Connect a signal generator to the RF signal input port. Set it to
the desired RF frequency at a power level of -15 dBm or less
to the evaluation board, but do NOT enable the RF signal.
3. Connect a spectrum analyzer to the RF signal output port.
4. Enable the power supply.
5. Enable the RF signal.
6. Take measurements.
CAUTION: If the input signal exceeds the rated power, the
SKY65045-70LF Evaluation Board can be permanently
damaged.
NOTE: It is important that the V_CC voltage source be adjusted
such that 5 V is measured at the board. The high collector
currents will drop the collector voltage significantly if long
leads are used. Adjust the bias voltage to compensate.
Evaluation Board
RF In
C2
C1
C3
R1
C7
C8
C9
C5
L5 C4
C6
RF Out
S708
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [e-mail] • www.skyworksinc.com
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December 3, 2008 • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • 200960 Rev. E