SKY85402-11 Datasheet, PDF (6/13 Pages) Skyworks Solutions Inc. – Linear output power for IEEE 802.11ac 256-QAM

PRELIMINARY DATA SHEET • SKY85402-11: HIGH-POWER (+22 dBm) 802.11ac WLAN PA
–50
–52
–54
–56
–58
–60
–62
–64
–66
–68
–70
5200
2nd Harmonics
3rd Harmonics
5300
5400
5500
5600
5700
5800
Frequency (MHz)
Figure 9. Harmonics vs Frequency
(@ +25 dBm)
Evaluation Board Description
The SKY85402-11 Evaluation Board is used to test the
performance of the SKY85402-11 WLAN PA. A schematic diagram
of the SKY85402-11 Evaluation Board is shown in Figure 10. A
photograph of the Evaluation Board is shown in Figure 11.
Component values for the SKY85402-11 Evaluation Board are
listed in Table 7.
Evaluation Board Setup Procedure
1. Connect system ground to pin 2 of connector J6.
2. Apply 5.0 V to pin 7 of connector J6.
3. By applying 3.3 V on PA_EN (pin 6 of the J5 header), the PA is
enabled. By placing a ground on PA_EN, the PA is disabled and
placed in a shutdown state, drawing minimal current.
4. The 5 GHz amplifier performance can be monitored by applying
an RF signal to connector J2 (RF_IN). Monitor the output power
on the RF_OUT port connector, J1.
5. Detector performance can be monitored on pin 4 of connector
J5.
CAUTION: Do not overdrive the amplifier by applying too much
RF on the device input. A suitable starting input power
setting is –20 dBm.
Circuit Design Considerations
The following design considerations are general in nature and
must be followed regardless of final use or configuration:
 Paths to ground should be made as short as possible.
 The ground pad of the SKY85402-11 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
device.
Therefore, design the connection to the ground pad to dissipate
the maximum wattage produced by the circuit board. Multiple
vias to the grounding layer are required. For further information,
refer to the Skyworks Application Note PCB Design Guidelines
for High Power Dissipation Packages, document number
201211.
 Bypass capacitors should be used on the DC supply lines. Refer
to the schematic drawing in Figure 10 for further details.
 The RF lines should be well separated from each other with
solid ground in between traces to maximize input-to-output
isolation.
 The RF_IN and RF_OUT ports are DC short to ground. These
ports need to be DC blocked with general purpose 10 pF
capacitors if there is DC present on the traces connecting to the
ports.
 The RF_IN and RF_OUT trace losses measured from device pin
to SMA connector are 0.2 dB each.
NOTE: A poor connection between the ground pad and ground
increases junction temperature (TJ), which reduces the life
of the device.
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [e-mail] • www.skyworksinc.com
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June 2, 2015 • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice • 202120I