SKY65105 Datasheet, PDF (5/11 Pages) Skyworks Solutions Inc. – 1700 - 2200 MHz Linear Power Amplifier

–35
–40
–40 ^oC
+25 ^oC
–45
+85 ^oC
–50
–55
–60
–65
–70
10
12
14
16
18
20
22
24
26
28
POUT (dBm)
Figure 9. Typical ACPR vs POUT Over Temperature
(Using CDMA IS-95 Downlink Signal With Nine Channels)
PRELIMINARY DATA SHEET • SKY65105 POWER AMPLIFIER
–30
–35
–40 ^oC
+25 ^oC
–40
+85 ^oC
–45
–50
–55
–60
–65
10
12
14
16
18
20
22
24
26
POUT (dBm)
Figure 10. Typical ACLR vs POUT Over Temperature
(Using WCDMA 3GPP Downlink Test Model 1 With 64 DPCH)
Evaluation Board Description
Skyworks SKY65105 Evaluation Board is used to test the
performance of the SKY65105 PA. The Evaluation Board
schematic diagram is shown in Figure 11. The schematic shows
the basic design of the board for the 1700 to 2200 MHz range. An
assembly drawing for the Evaluation Board is shown in Figure 12
and the layer detail is provided in Figure 13.
Circuit Design Considerations
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 SKY65105 PA 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
amplifier. As such, design the connection to the ground pad to
dissipate the maximum wattage produced to the circuit board.
Multiple vias to the grounding layer are required.
3. Two external output bypass capacitors (0.01 µF and 4.7 µF)
are required on the VCC1 (pin 12) supply input. The same two
capacitors are also required on the VCC2 (pin 4) supply input.
Both capacitors should be placed in parallel between the
supply line and ground. Also, a bypass capacitor of 0.01 µF is
required on the VREF input (pin 3). See Figure 11 for a detailed
diagram.
4. VCC1 (pin 12) and VCC2 (pin 4) may be connected together at
the supply.
5. At the RF input (pin 2), a DC blocking capacitor is required.
6. The RF output includes an onboard internal DC blocking
capacitor. All impedance matching is provided internally.
Therefore, the application only needs to provide a good 50 Ω
load.
Testing Procedure
Use the following procedure to set up the SKY65105 Evaluation
Board for testing. Refer to Figure 14 for guidance:
1. Connect a +5.0 V supply voltage to VCC1 and VCC2, and
+3.6 V supply voltage to VREF. If available, enable the current
limiting function of the power supplies to 1.0 A for the +5.0 V
supply current and 30 mA for the +3.6 V supply current.
2. Connect a signal generator to the RF signal input port. Set it to
the desired RF frequency at a power level of 7 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
SKY65105 Evaluation Board can be permanently
damaged.
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [e-mail] • www.skyworksinc.com
200085D • Skyworks Proprietary and Confidential information • Products and Product Information are Subject to Change Without Notice • July 13, 2007
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